Browse Source

webrtc update

Nikolay Suslov 7 years ago
parent
commit
dccb0bbac3

+ 1 - 1
public/webrtc/index.vwf.config.yaml

@@ -6,4 +6,4 @@ model:
 view:
   vwf/view/aframe:
   vwf/view/editor-new:
-  vwf/view/webrtc: { debug: false, videoProperties: { create: false }, iceServers: [ { url: 'stun:stun.l.google.com:19302' }, { url: 'stun:stun.sipgate.net' }, { url: 'stun:217.10.68.152' }, { url: 'stun:stun.sipgate.net:10000' }, { url: 'stun:217.10.68.152:10000' }, { url: 'stun:23.21.150.121:3478' }, { url: 'stun:216.93.246.18:3478' }, { url: 'stun:66.228.45.110:3478' }, { url: 'stun:173.194.78.127:19302' }, { url: 'stun:74.125.142.127:19302' }, { url: 'stun:provserver.televolution.net' }, { url: 'stun:sip1.lakedestiny.cordiaip.com' }, { url: 'stun:stun1.voiceeclipse.net' }, { url: 'stun:stun01.sipphone.com' }, { url: 'stun:stun.callwithus.com' }, { url: 'stun:stun.counterpath.net' }, { url: 'stun:stun.endigovoip.com' } ] }
+  vwf/view/webrtc: { iceServers: [ { url: 'stun:stun.l.google.com:19302' }, { url: 'stun:stun1.l.google.com:19302' },  { url: 'stun:stun2.l.google.com:19302' }, { url: 'stun:stun3.l.google.com:19302' }] }

+ 1 - 1
support/client/lib/index.html

@@ -31,7 +31,7 @@
 
     <script type="text/javascript" src="socket.io/socket.io.js"></script>
     <!-- <script type="text/javascript" src="socket.io-sessionid-patch.js"></script> -->
-    <script src="vwf/view/webrtc/adapter-latest.js"></script>
+    <script src="vwf/view/webrtc/dist/adapter-latest.js"></script>
 
 
     <script type="text/javascript" src="vwf/view/lib/cell.js"></script>

+ 1102 - 0
support/client/lib/vwf/view/webrtc.1.js

@@ -0,0 +1,1102 @@
+"use strict";
+
+// Copyright 2012 United States Government, as represented by the Secretary of Defense, Under
+// Secretary of Defense (Personnel & Readiness).
+// 
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+// in compliance with the License. You may obtain a copy of the License at
+// 
+//   http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software distributed under the License
+// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+// or implied. See the License for the specific language governing permissions and limitations under
+// the License.
+
+/// @module vwf/view/webrtc
+/// @requires vwf/view
+
+define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ], function( module, view, utility, Color, $ ) {
+
+    return view.load( module, {
+
+        // == Module Definition ====================================================================
+
+        initialize: function( options ) {
+
+            if ( !this.state ) {   
+                this.state = {};
+            }
+            
+            this.state.clients = {};
+            this.state.instances = {};
+            this.local = {
+                "ID": undefined,
+                "url": undefined,
+                "stream": undefined,
+                "sharing": { audio: true, video: true } 
+            };
+
+            // turns on logger debugger console messages 
+            this.debugVwf = {
+                "creation": false,
+                "initializing": false,
+                "parenting": false,
+                "deleting": false,
+                "properties": false,
+                "setting": false,
+                "getting": false,
+                "calling": false
+            };
+
+            if ( options === undefined ) { options = {}; }
+
+            this.stereo = options.stereo !== undefined  ? options.stereo : false;
+            this.videoElementsDiv = options.videoElementsDiv !== undefined  ? options.videoElementsDiv : 'videoSurfaces';
+            this.videoProperties = options.videoProperties !== undefined  ? options.videoProperties : {};
+            this.bandwidth = options.bandwidth;
+            this.iceServers = options.iceServers !== undefined  ? options.iceServers : [ { "url": "stun:stun.l.google.com:19302" } ];
+            this.debug = options.debug !== undefined ? options.debug : false;
+
+            this.videosAdded = 0;
+            this.msgQueue = [];
+
+        },
+  
+        createdNode: function( nodeID, childID, childExtendsID, childImplementsIDs,
+            childSource, childType, childIndex, childName, callback /* ( ready ) */ ) {
+
+            if ( this.debugVwf.creation ) {
+                this.kernel.logger.infox( "createdNode", nodeID, childID, childExtendsID, childImplementsIDs, childSource, childType, childName );
+            }
+
+            if ( childExtendsID === undefined )
+                return;
+
+            var self = this, node;
+            
+            var protos = getPrototypes.call( self, childExtendsID )
+   
+            if ( isClientInstanceDef.call( this, protos ) && childName ) {
+                
+                node = {
+                    "parentID": nodeID,
+                    "ID": childID,
+                    "extendsID": childExtendsID,
+                    "implementsIDs": childImplementsIDs,
+                    "source": childSource,
+                    "type": childType,
+                    "name": childName,
+                    "prototypes": protos,
+                };
+
+                this.state.instances[ childID ] = node;
+
+            } else if ( isClientDefinition.call( this, protos ) && childName ) {
+
+                // check if this instance of client and if this client is for this instance
+                // create a login for this 
+                node = {
+                    "parentID": nodeID,
+                    "ID": childID,
+                    "moniker": undefined,
+                    "extendsID": childExtendsID,
+                    "implementsIDs": childImplementsIDs,
+                    "source": childSource,
+                    "type": childType,
+                    "name": childName,
+                    "prototypes": protos,
+                    "displayName": "",
+                    "connection": undefined,
+                    "localUrl": undefined, 
+                    "remoteUrl": undefined,
+                    //"color": "rgb(0,0,0)",
+                    "createProperty": true, 
+                    "sharing": { audio: true, video: true }                   
+                };
+
+                this.state.clients[ childID ] = node;
+                
+                // add the client specific locals
+                node.moniker = appMoniker.call( this, childName );
+                //console.info( "new client moniker: " + node.moniker );
+                node.displayName = undefined;
+                node.prototypes = protos;
+
+                if ( this.kernel.moniker() == node.moniker ) { 
+                    this.local.ID = childID;
+                    
+                    if ( this.videoElementsDiv ) {
+                        $('body').append(
+                            "<div id='"+self.videoElementsDiv+"'></div>"
+                        );                   
+                    }
+                } 
+            }
+
+        }, 
+
+        initializedNode: function( nodeID, childID, childExtendsID, childImplementsIDs, 
+            childSource, childType, childIndex, childName ) {
+
+            if ( this.debugVwf.initializing ) {
+                this.kernel.logger.infox( "initializedNode", nodeID, childID, childExtendsID, childImplementsIDs, childSource, childType, childName );
+            } 
+
+            if ( childExtendsID === undefined )
+                return;
+
+            var client = this.state.clients[ childID ];
+
+            if ( client ) {
+                if ( this.local.ID == childID ){
+                    
+                    // local client object
+                    // grab access to the webcam 
+                    capture.call( this, this.local.sharing );
+                   
+                    var remoteClient = undefined;
+                    // existing clients
+                    for ( var clientID in this.state.clients ) {
+                        
+                        if ( clientID != this.local.ID ) {
+                            // create property for this client on each existing client
+                            remoteClient = this.state.clients[ clientID ];
+
+                            if ( remoteClient.createProperty ) {
+                                //console.info( "++ 1 ++    createProperty( "+clientID+", "+this.kernel.moniker()+" )" );  
+                                remoteClient.createProperty = false;
+                                this.kernel.createProperty( clientID, this.kernel.moniker() );                                
+                            }                          
+                        }
+                    }
+                } else {
+                    // not the local client, but if the local client has logged
+                    // in create the property for this on the new client
+                    if ( this.local.ID )   {
+                        if ( client.createProperty ) {
+                            client.createProperty = false;
+                            //console.info( "++ 2 ++    createProperty( "+childID+", "+this.kernel.moniker()+" )" );
+                            this.kernel.createProperty( childID, this.kernel.moniker() );
+                        }
+                    }
+                }
+            }            
+        },
+
+        deletedNode: function( nodeID ) {
+            
+            if ( this.debugVwf.deleting ) {
+                this.kernel.logger.infox( "deletedNode", nodeID );
+            }
+            // debugger;
+
+            //if ( this.kernel.find( nodeID, "parent::element(*,'http://vwf.example.com/clients.vwf')" ).length > 0 ) {
+                //if ( this.kernel.find( nodeID ).length > 0 ) {
+                var moniker = nodeID.slice(-20);//this.kernel.name( nodeID );
+                var client = undefined;
+
+                if ( moniker == this.kernel.moniker() ) {
+                    
+                    // this is the client that has left the converstaion
+                    // go through the peerConnections and close the 
+                    // all current connections
+                    var peer, peerMoniker;
+                    for ( var peerID in this.state.clients ) {
+                        peer = this.state.clients[ peerID ];
+                        peerMoniker = appMoniker.call( this, peer.name )
+                        if ( peerMoniker != this.kernel.moniker ) {
+                            peer.connection && peer.connection.disconnect();
+                        }
+                    }
+
+                } else {
+
+                    // this is a client who has has a peer leave the converstaion
+                    // remove that client, and the 
+                    client = findClientByMoniker.call( this, moniker );
+                    if ( client ) {
+                        client.connection && client.connection.disconnect();
+
+                        removeClient.call( this, client );
+                        delete this.state.clients[ client ]
+                    }
+
+                     
+                }
+            //}         
+
+        },
+  
+        createdProperty: function( nodeID, propertyName, propertyValue ) {
+
+            if ( this.debugVwf.properties ) {
+                this.kernel.logger.infox( "C === createdProperty ", nodeID, propertyName, propertyValue );
+            }
+
+            this.satProperty( nodeID, propertyName, propertyValue );
+        },        
+
+        initializedProperty: function( nodeID, propertyName, propertyValue ) {
+
+            if ( this.debugVwf.properties ) {
+                this.kernel.logger.infox( "  I === initializedProperty ", nodeID, propertyName, propertyValue );
+            }
+
+            this.satProperty( nodeID, propertyName, propertyValue );
+        },        
+
+        satProperty: function( nodeID, propertyName, propertyValue ) {
+            
+            
+            if ( this.debugVwf.properties || this.debugVwf.setting ) {
+                this.kernel.logger.infox( "    S === satProperty ", nodeID, propertyName, propertyValue );
+            } 
+
+            var client = this.state.clients[ nodeID ];
+
+            if ( client ) {
+                switch( propertyName ) {
+                    
+                    case "sharing":
+                        if ( propertyValue ) {
+                            client.sharing = propertyValue;
+                            if ( nodeID == this.local.ID ) {
+                                updateSharing.call( this, nodeID, propertyValue );
+                            }
+                        }
+                        break;
+
+                    case "localUrl":
+                        if ( propertyValue ) {
+                            if ( nodeID != this.local.ID ) {
+                                client.localUrl = propertyValue;
+                            }
+                        }
+                        break;
+
+                    case "remoteUrl":
+                        if ( propertyValue ) {
+                            client.remoteUrl = propertyValue;
+                         }
+                        break;
+
+                    case "displayName":
+                        if ( propertyValue ) {
+                            client.displayName = propertyValue;
+                        }
+                        break; 
+
+                    case "color":
+                        var clr = new utility.color( propertyValue );
+                        if ( clr ) {
+                            client.color = clr.toString();
+                        }
+                        break;    
+
+                    default:  
+                        // propertyName is the moniker of the client that 
+                        // this connection supports
+                        if ( nodeID == this.local.ID ) {
+                            if ( propertyValue ) {
+                                // propertyName - moniker of the client
+                                // propertyValue - peerConnection message
+                                handlePeerMessage.call( this, propertyName, propertyValue );
+                            }
+                        }
+                        break;
+                }
+            }
+        },
+
+        gotProperty: function( nodeID, propertyName, propertyValue ) {
+
+            if ( this.debugVwf.properties || this.debugVwf.getting ) {
+                this.kernel.logger.infox( "   G === gotProperty ", nodeID, propertyName, propertyValue );
+            }
+            var value = undefined;
+
+            return value;
+        },
+
+        calledMethod: function( nodeID, methodName, methodParameters, methodValue ) {
+            
+            if ( this.debugVwf.calling ) {
+                this.kernel.logger.infox( "  CM === calledMethod ", nodeID, methodName, methodParameters );
+            }
+
+            switch ( methodName ) {
+                case "setLocalMute":
+                    if ( this.kernel.moniker() == this.kernel.client() ) {
+                        methodValue = setMute.call( this, methodParameters );
+                    }
+                    break;
+            }
+        },       
+
+        firedEvent: function( nodeID, eventName, eventParameters ) {
+        },
+
+    } );
+ 
+    function createVideoElementAsAsset(id) {
+        
+          var video = document.querySelector('#' + id);
+        
+          if (!video) {
+            video = document.createElement('video');
+          }
+        
+          video.setAttribute('id', id);
+          video.setAttribute('autoplay', true);
+          video.setAttribute('src', '');
+          video.setAttribute("webkit-playsinline", true);
+          video.setAttribute("controls", true);
+          video.setAttribute("width", 640);
+          video.setAttribute("height", 480);
+        
+          var assets = document.querySelector('a-assets');
+        
+        //   if (!assets) {
+        //     assets = document.createElement('a-assets');
+        //     document.querySelector('a-scene').appendChild(assets);
+        //   }
+        
+          if (!assets.contains(video)) {
+            assets.appendChild(video);
+          }
+        
+          return video;
+        }
+
+
+    function getPrototypes( extendsID ) {
+        var prototypes = [];
+        var id = extendsID;
+
+        while ( id !== undefined ) {
+            prototypes.push( id );
+            id = this.kernel.prototype( id );
+        }
+                
+        return prototypes;
+    }
+
+    function getPeer( moniker ) {
+        var clientNode;
+        for ( var id in this.state.clients ) {
+            if ( this.state.clients[id].moniker == moniker ) {
+                clientNode = this.state.clients[id];
+                break;
+            }
+        }
+        return clientNode;
+    }
+
+    function displayLocal( stream, name, color ) {
+        var id = this.kernel.moniker();
+        return displayVideo.call( this, id, stream, this.local.url, name, id, true, color );
+    }
+
+    function displayVideo( id, stream, url, name, destMoniker, muted, color ) {
+        
+        var divId = undefined;
+
+        if ( this.videoProperties.create ) {
+            this.videosAdded++
+            var $container;
+            divId = name + this.videosAdded;
+            var videoId = "video-" + divId;
+
+            $container = $( "#" + this.videoElementsDiv );
+            if ( muted ) {
+                $container.append(
+                    "<div id='"+ divId + "'>" +
+                        "<video class='vwf-webrtc-video' id='" + videoId +
+                            "' width='320' height='240' " +
+                            "loop='loop' autoplay muted " +
+                            "style='position: absolute; left: 0; top: 0; z-index: 40;'>" +
+                        "</video>" +
+                    "</div>"
+                );
+
+            } else {
+                $container.append(
+                    "<div id='"+ divId + "'>" +
+                        "<video class='vwf-webrtc-video' id='" + videoId +
+                            "' width='320' height='240'" +
+                            " loop='loop' autoplay " +
+                            "style='position: absolute; left: 0; top: 0; z-index: 40;'>" +
+                        "</video>" +
+                    "</div>"
+                );
+            }
+            
+            var videoE = $( '#'+ videoId )[0];
+            if ( videoE && stream ) {
+                navigator.attachMediaStream( videoE, stream );
+                if ( muted ) {
+                    videoE.muted = true;  // firefox isn't mapping the muted property correctly
+                }
+            }  
+
+            var divEle = $('#'+divId);
+            divEle && divEle.draggable && divEle.draggable();
+           
+        } 
+
+        var clr = new utility.color( color );
+        if ( clr ) { 
+            clr = clr.toArray(); 
+        }
+
+        this.kernel.callMethod( this.kernel.application(), "createVideo", [ {
+            "ID": id,
+            "url": url, 
+            "name": name, 
+            "muted": muted, 
+            "color": clr ? clr : color
+        }, destMoniker ] );       
+        
+        
+        let video = createVideoElementAsAsset(name);
+        video.srcObject = stream;
+
+       this.kernel.callMethod( 'avatar-'+id, "setVideoTexture", [name]);
+
+        return divId;
+    }
+
+    function removeVideo( client ) {
+        
+        if ( client.videoDivID ) {
+            var $videoWin = $( "#" + client.videoDivID );
+            if ( $videoWin ) {
+                $videoWin.remove();
+            }
+            client.videoDivID = undefined;
+        }
+
+        this.kernel.callMethod( this.kernel.application(), "removeVideo", [ client.moniker ] );
+
+    }
+
+    function displayRemote( id, stream, url, name, destMoniker, color ) {
+        return displayVideo.call( this, id, stream, url, name, destMoniker, false, color );
+    }
+
+    function capture( media ) {
+
+        if ( this.local.stream === undefined && ( media.video || media.audio ) ) {
+            var self = this;
+            var constraints = { 
+                "audio": media.audio, 
+                "video": media.video ? { "mandatory": {}, "optional": [] } : false, 
+            };
+            
+            var successCallback = function( stream ) {
+                self.local.url = URL.createObjectURL( stream );
+                self.local.stream = stream;
+
+                self.kernel.setProperty( self.local.ID, "localUrl", self.local.url );
+
+                var localNode = self.state.clients[ self.local.ID ];
+                displayLocal.call( self, stream, localNode.displayName, localNode.color );
+                sendOffers.call( self );
+            };
+
+            var errorCallback = function( error ) { 
+                console.log("failed to get video stream error: " + error); 
+            };
+
+            try { 
+                navigator.getUserMedia( constraints, successCallback, errorCallback );
+            } catch (e) { 
+                console.log("getUserMedia: error " + e ); 
+            };
+        }
+    }  
+
+    function appMoniker( name ) {
+        return name.substr( 7, name.length-1 );
+    }
+    
+    function findClientByMoniker( moniker ) {
+        var client = undefined;
+        for ( var id in this.state.clients ) {
+            if ( client === undefined && moniker == this.state.clients[ id ].moniker ) {
+                client = this.state.clients[ id ];
+            }
+        }
+        return client;
+    }
+
+    function removeClient( client ) {
+        if ( client ) {
+            removeVideo.call( this, client );
+        }
+    }
+
+    function sendOffers() {
+        var peerNode;
+        for ( var id in this.state.clients ) {
+            if ( id != this.local.ID ) {
+                peerNode = this.state.clients[ id ];
+                
+                // if there's a url then connect                     
+                if ( peerNode.localUrl && peerNode.localUrl != "" && peerNode.connection === undefined ) {
+                    createPeerConnection.call( this, peerNode, true );   
+                }                
+            }
+        }
+        
+
+    }
+
+    function updateSharing( nodeID, sharing ) {
+        setMute.call( this, !sharing.audio );
+        setPause.call( this, !sharing.video );
+    }
+
+
+    function setMute( mute ) {
+        if ( this.local.stream && this.local.stream.audioTracks && this.local.stream.audioTracks.length > 0 ) {
+          if ( mute !== undefined ) {
+            this.local.stream.audioTracks[0].enabled = !mute;
+          }
+        }
+    };
+
+    function setPause( pause ) {
+        if ( this.local.stream && this.local.stream.videoTracks && this.local.stream.videoTracks.length > 0 ) {
+            if ( pause !== undefined ) {
+                this.local.stream.videoTracks[0].enabled = !pause;
+            }
+        }
+    }
+
+    function release() {
+      for ( id in this.connections ) {
+          this.connections[id].disconnect();
+      } 
+      this.connections = {};
+    }  
+
+    function hasStream() {
+        return ( this.stream !== undefined );
+    }
+
+    function createPeerConnection( peerNode, sendOffer ) {
+        if ( peerNode ) {
+            if ( peerNode.connection === undefined ) {
+                peerNode.connection = new mediaConnection( this, peerNode );
+                peerNode.connection.connect( this.local.stream, sendOffer );
+
+                //if ( this.bandwidth !== undefined ) {
+                //    debugger;
+                //}
+            }
+        }
+    }
+
+    function handlePeerMessage( propertyName, msg ) {
+        var peerNode = getPeer.call( this, propertyName )
+        if ( peerNode ) {
+            if ( peerNode.connection !== undefined ) {
+                peerNode.connection.processMessage( msg );
+            } else {
+                if ( msg.type === 'offer' ) {
+                    
+                    this.msgQueue.unshift( msg );
+
+                    peerNode.connection = new mediaConnection( this, peerNode );
+                    peerNode.connection.connect( this.local.stream, false );
+
+                    while ( this.msgQueue.length > 0 ) {
+                      peerNode.connection.processMessage( this.msgQueue.shift() );
+                    }
+                    this.msgQueue = [];
+                } else {
+                    this.msgQueue.push( msg );
+                }
+            }
+        }     
+    }
+
+    function deletePeerConnection( peerID ) {
+        var peerNode = this.state.clients[ peerID ];
+        if ( peerNode ) {
+            peerNode.connection.disconnect();
+            peerNode.connection = undefined;
+        }
+    } 
+
+    function getConnectionStats() {
+        var peerNode = undefined;
+        for ( var id in this.state.clients ) {
+            peerNode = this.state.clients[ id ];
+            if ( peerNode && peerNode.connection ) {
+                peerNode.connection.getStats();
+            }
+        } 
+    }
+
+    function isClientDefinition( prototypes ) {
+        var foundClient = false;
+        if ( prototypes ) {
+            var len = prototypes.length;
+            for ( var i = 0; i < len && !foundClient; i++ ) {
+                foundClient = ( prototypes[i] == "http://vwf.example.com/aframe/avatar.vwf" );
+            }
+        }
+
+        return foundClient;
+    }
+
+    function isClientInstanceDef( nodeID ) {
+        return ( nodeID == "http://vwf.example.com/clients.vwf" );
+    }
+
+    function mediaConnection( view, peerNode ) {
+        this.view = view;
+        this.peerNode = peerNode;        
+        
+        // 
+        this.stream = undefined;
+        this.url = undefined;
+        this.pc = undefined;
+        this.connected = false;
+        this.streamAdded = false;
+        this.state = "created";
+
+        // webrtc peerConnection parameters
+        this.pc_config = { "iceServers": this.view.iceServers };
+        this.pc_constraints = { "optional": [ { "DtlsSrtpKeyAgreement": true } ] };
+        // Set up audio and video regardless of what devices are present.
+        this.sdpConstraints = { 'mandatory': {
+                                'OfferToReceiveAudio':true, 
+                                'OfferToReceiveVideo':true }};
+
+        this.connect = function( stream, sendOffer ) {
+            var self = this;
+            if ( this.pc === undefined ) {
+                if ( this.view.debug ) console.log("Creating PeerConnection.");
+                
+                var iceCallback = function( event ) {
+                    //console.log( "------------------------ iceCallback ------------------------" );
+                    if ( event.candidate ) {
+                        var sMsg = { 
+                            "type": 'candidate',
+                            "label": event.candidate.sdpMLineIndex,
+                            "id": event.candidate.sdpMid,
+                            "candidate": event.candidate.candidate
+                        };
+
+                        // each client creates a property for each other
+                        // the message value is broadcast via the property
+                        self.view.kernel.setProperty( self.peerNode.ID, self.view.kernel.moniker(), sMsg );
+                    } else {
+                        if ( self.view.debug ) console.log("End of candidates.");
+                    }
+                }; 
+
+                // if ( webrtcDetectedBrowser == "firefox" ) {
+                //     this.pc_config = {"iceServers":[{"url":"stun:23.21.150.121"}]};
+                // }
+
+                try {
+                    this.pc = new RTCPeerConnection( this.pc_config, this.pc_constraints );
+                    this.pc.onicecandidate = iceCallback;
+
+                    if ( self.view.debug ) console.log("Created RTCPeerConnnection with config \"" + JSON.stringify( this.pc_config ) + "\".");
+                } catch (e) {
+                    console.log("Failed to create PeerConnection, exception: " + e.message);
+                    alert("Cannot create RTCPeerConnection object; WebRTC is not supported by this browser.");
+                    return;
+                } 
+
+                this.pc.onnegotiationeeded = function( event ) {
+                    //debugger;
+                    //console.info( "onnegotiationeeded." );
+                }
+
+                this.pc.onaddstream = function( event ) {
+                    if ( self.view.debug ) console.log("Remote stream added.");
+                    
+                    self.stream = event.stream;
+                    self.url = URL.createObjectURL( event.stream );
+                    
+                    if ( self.view.debug ) console.log("Remote stream added.  url: " + self.url );
+
+                    var divID = displayRemote.call( self.view, self.peerNode.moniker, self.stream, self.url, self.peerNode.displayName, view.kernel.moniker(), self.peerNode.color );
+                    if ( divID !== undefined ) {
+                        self.peerNode.videoDivID = divID;
+                    }
+                };
+
+                this.pc.onremovestream = function( event ) {
+                    if ( self.view.debug ) console.log("Remote stream removed.");
+                };
+
+                this.pc.onsignalingstatechange = function() {
+                    //console.info( "onsignalingstatechange state change." );
+                }
+
+                this.pc.oniceconnectionstatechange = function( ) {
+                    if ( self && self.pc ) {
+                        var state = self.pc.signalingState || self.pc.readyState;
+                        //console.info( "peerConnection state change: " + state );
+                    } 
+                }
+
+                if ( stream ) {
+                    if ( this.view.debug ) console.log("Adding local stream.");
+
+                    this.pc.addStream( stream );
+                    this.streamAdded = true;
+                }
+
+                if ( sendOffer ){
+                    this.call();
+                }
+            }
+            this.connected = ( this.pc !== undefined );
+        };
+
+        this.setMute = function( mute ) {
+            if ( this.stream && this.stream.audioTracks && this.stream.audioTracks.length > 0 ) {
+                if ( mute !== undefined ) {
+                    this.stream.audioTracks[0].enabled = !mute;
+                }
+            }
+        }
+
+        this.setPause = function( pause ) {
+            if ( this.stream && this.stream.videoTracks && this.stream.videoTracks.length > 0 ) {
+                if ( pause !== undefined ) {
+                    this.stream.videoTracks[0].enabled = !pause;
+                }
+            }
+        }
+
+        this.disconnect = function() {
+            if ( this.view.debug ) console.log( "PC.disconnect  " + this.peerID );
+            
+            if ( this.pc ) {
+                this.pc.close();
+                this.pc = undefined;
+            }
+        };
+
+        this.processMessage = function( msg ) {
+            //var msg = JSON.parse(message); 
+            if ( this.view.debug ) console.log('S->C: ' +  JSON.stringify(msg) );
+            if ( this.pc ) {
+                if ( msg.type === 'offer') {
+                    if ( this.view.stereo ) {
+                        msg.sdp = addStereo( msg.sdp );
+                    }
+                    this.pc.setRemoteDescription( new RTCSessionDescription( msg ) );
+                    this.answer();
+                } else if ( msg.type === 'answer' && this.streamAdded ) {
+                    if ( this.view.stereo ) {
+                        msg.sdp = addStereo( msg.sdp );
+                    }                    
+                    this.pc.setRemoteDescription( new RTCSessionDescription( msg ) );
+                } else if ( msg.type === 'candidate' && this.streamAdded ) {
+                    var candidate = new RTCIceCandidate( { 
+                        "sdpMLineIndex": msg.label,
+                        "candidate": msg.candidate 
+                    } );
+                    this.pc.addIceCandidate( candidate );
+                } else if ( msg.type === 'bye' && this.streamAdded ) {
+                    this.hangup();
+                }
+            } 
+        };
+
+        this.answer = function() {
+            if ( this.view.debug ) console.log( "Send answer to peer" );
+            
+            var self = this;
+            var answerer = function( sessionDescription ) {
+                // Set Opus as the preferred codec in SDP if Opus is present.
+                sessionDescription.sdp = self.preferOpus( sessionDescription.sdp );
+                sessionDescription.sdp = self.setBandwidth( sessionDescription.sdp );
+
+                self.pc.setLocalDescription( sessionDescription );
+
+                self.view.kernel.setProperty( self.peerNode.ID, self.view.kernel.moniker(), sessionDescription );
+            };
+
+            this.pc.createAnswer( answerer, null, this.sdpConstraints);
+        };
+
+        this.call = function() {
+            var self = this;
+            var constraints = {
+                "optional": [], 
+                "mandatory": {}
+            };
+
+            // temporary measure to remove Moz* constraints in Chrome
+            if ( navigator.webrtcDetectedBrowser === "chrome" ) {
+                for ( var prop in constraints.mandatory ) {
+                    if ( prop.indexOf("Moz") != -1 ) {
+                        delete constraints.mandatory[ prop ];
+                    }
+                }
+            }   
+            constraints = this.mergeConstraints( constraints, this.sdpConstraints );
+
+            if ( this.view.debug ) console.log("Sending offer to peer, with constraints: \n" +  "  \"" + JSON.stringify(constraints) + "\".")
+          
+            var offerer = function( sessionDescription ) {
+                // Set Opus as the preferred codec in SDP if Opus is present.
+                sessionDescription.sdp = self.preferOpus( sessionDescription.sdp );
+
+                sessionDescription.sdp = self.setBandwidth( sessionDescription.sdp );
+                self.pc.setLocalDescription( sessionDescription );
+                
+                //sendSignalMessage.call( sessionDescription, self.peerID );
+                self.view.kernel.setProperty( self.peerNode.ID, self.view.kernel.moniker(), sessionDescription );
+            };
+
+            var onFailure = function(e) {
+                console.log(e)
+            }
+
+            this.pc.createOffer( offerer, onFailure, constraints );
+        };
+
+        this.setBandwidth = function( sdp ) {
+
+            // apparently this only works in chrome
+            if ( this.bandwidth === undefined || moz ) {
+                return sdp;
+            }
+
+            // remove existing bandwidth lines
+            sdp = sdp.replace(/b=AS([^\r\n]+\r\n)/g, '');
+            
+            if ( this.bandwidth.audio ) {
+                sdp = sdp.replace(/a=mid:audio\r\n/g, 'a=mid:audio\r\nb=AS:' + this.bandwidth.audio + '\r\n');
+            }
+
+            if ( this.bandwidth.video ) {
+                sdp = sdp.replace(/a=mid:video\r\n/g, 'a=mid:video\r\nb=AS:' + this.bandwidth.video + '\r\n');
+            }
+
+            if ( this.bandwidth.data /*&& !options.preferSCTP */ ) {
+                sdp = sdp.replace(/a=mid:data\r\n/g, 'a=mid:data\r\nb=AS:' + this.bandwidth.data + '\r\n');
+            }
+            return sdp;
+        }
+
+        this.getStats = function(){
+          if ( this.pc && this.pc.getStats ) {
+            console.info( "pc.iceConnectionState = " + this.pc.iceConnectionState );
+            console.info( " pc.iceGatheringState = " + this.pc.iceGatheringState );
+            console.info( "        pc.readyState = " + this.pc.readyState );
+            console.info( "    pc.signalingState = " + this.pc.signalingState );
+
+            var consoleStats = function( obj ) {
+                console.info( '   Timestamp:' + obj.timestamp );
+                if ( obj.id ) {
+                    console.info( '        id: ' + obj.id );
+                }
+                if ( obj.type ) {
+                    console.info( '        type: ' + obj.type );
+                }
+                if ( obj.names ) {
+                    var names = obj.names();
+                    for ( var i = 0; i < names.length; ++i ) {
+                        console.info( "         "+names[ i ]+": " + obj.stat( names[ i ] ) );
+                    }
+                } else {
+                    if ( obj.stat && obj.stat( 'audioOutputLevel' ) ) {
+                        console.info( "         audioOutputLevel: " + obj.stat( 'audioOutputLevel' ) );
+                    }
+                }
+            };
+
+            // local function
+            var readStats = function( stats ) {
+                var results = stats.result();
+                var bitrateText = 'No bitrate stats';
+
+                for ( var i = 0; i < results.length; ++i ) {
+                    var res = results[ i ];
+                    console.info( 'Report ' + i );
+                    if ( !res.local || res.local === res ) {
+                        
+                        consoleStats( res );
+                        // The bandwidth info for video is in a type ssrc stats record
+                        // with googFrameHeightReceived defined.
+                        // Should check for mediatype = video, but this is not
+                        // implemented yet.
+                        if ( res.type == 'ssrc' && res.stat( 'googFrameHeightReceived' ) ) {
+                            var bytesNow = res.stat( 'bytesReceived' );
+                            if ( timestampPrev > 0) {
+                                var bitRate = Math.round( ( bytesNow - bytesPrev ) * 8 / ( res.timestamp - timestampPrev ) );
+                                bitrateText = bitRate + ' kbits/sec';
+                            }
+                            timestampPrev = res.timestamp;
+                            bytesPrev = bytesNow;
+                        }
+                    } else {
+                        // Pre-227.0.1445 (188719) browser
+                        if ( res.local ) {
+                            console.info( "  Local: " );
+                            consoleStats( res.local );
+                        }
+                        if ( res.remote ) {
+                            console.info( "  Remote: " );
+                            consoleStats( res.remote );
+                        }
+                    }
+                }
+                console.info( "    bitrate: " + bitrateText )
+            } 
+
+            this.pc.getStats( readStats );        
+          }
+        }
+
+        this.hangup = function() {
+            if ( this.view.debug ) console.log( "PC.hangup  " + this.id );
+            
+            if ( this.pc ) {
+                this.pc.close();
+                this.pc = undefined;
+            }
+        };
+
+        this.mergeConstraints = function( cons1, cons2 ) {
+            var merged = cons1;
+            for (var name in cons2.mandatory) {
+                merged.mandatory[ name ] = cons2.mandatory[ name ];
+            }
+            merged.optional.concat( cons2.optional );
+            return merged;
+        }
+
+        // Set Opus as the default audio codec if it's present.
+        this.preferOpus = function( sdp ) {
+            var sdpLines = sdp.split( '\r\n' );
+
+            // Search for m line.
+            for ( var i = 0; i < sdpLines.length; i++ ) {
+                if ( sdpLines[i].search( 'm=audio' ) !== -1 ) {
+                    var mLineIndex = i;
+                    break;
+                } 
+            }
+
+            if ( mLineIndex === null ) {
+                return sdp;
+            }
+
+            // for ( var i = 0; i < sdpLines.length; i++ ) {
+            //     if ( i == 0 ) console.info( "=============================================" );
+                
+            //     console.info( "sdpLines["+i+"] = " + sdpLines[i] );
+            // }
+
+            // If Opus is available, set it as the default in m line.
+            for ( var i = 0; i < sdpLines.length; i++ ) {
+
+                if ( sdpLines[i].search( 'opus/48000' ) !== -1 ) {        
+                    var opusPayload = this.extractSdp( sdpLines[i], /:(\d+) opus\/48000/i );
+                    if ( opusPayload) {
+                        sdpLines[ mLineIndex ] = this.setDefaultCodec( sdpLines[ mLineIndex ], opusPayload );
+                    }
+                    break;
+                }
+            }
+
+            // Remove CN in m line and sdp.
+            sdpLines = this.removeCN( sdpLines, mLineIndex );
+
+            sdp = sdpLines.join('\r\n');
+            return sdp;
+        }
+
+        // Set Opus in stereo if stereo is enabled.
+        function addStereo( sdp ) {
+            var sdpLines = sdp.split('\r\n');
+
+            // Find opus payload.
+            for (var i = 0; i < sdpLines.length; i++) {
+              if (sdpLines[i].search('opus/48000') !== -1) {
+                var opusPayload = extractSdp(sdpLines[i], /:(\d+) opus\/48000/i);
+                break;
+              }
+            }
+
+            // Find the payload in fmtp line.
+            for (var i = 0; i < sdpLines.length; i++) {
+              if (sdpLines[i].search('a=fmtp') !== -1) {
+                var payload = extractSdp(sdpLines[i], /a=fmtp:(\d+)/ );
+                if (payload === opusPayload) {
+                  var fmtpLineIndex = i;
+                  break;
+                }
+              }
+            }
+            // No fmtp line found.
+            if (fmtpLineIndex === null)
+              return sdp;
+
+            // Append stereo=1 to fmtp line.
+            sdpLines[fmtpLineIndex] = sdpLines[fmtpLineIndex].concat(' stereo=1');
+
+            sdp = sdpLines.join('\r\n');
+            return sdp;
+        }
+
+        // Strip CN from sdp before CN constraints is ready.
+        this.removeCN = function( sdpLines, mLineIndex ) {
+            var mLineElements = sdpLines[mLineIndex].split( ' ' );
+            // Scan from end for the convenience of removing an item.
+            for ( var i = sdpLines.length-1; i >= 0; i-- ) {
+                var payload = this.extractSdp( sdpLines[i], /a=rtpmap:(\d+) CN\/\d+/i );
+                if ( payload ) {
+                    var cnPos = mLineElements.indexOf( payload );
+                    if ( cnPos !== -1 ) {
+                        // Remove CN payload from m line.
+                        mLineElements.splice( cnPos, 1 );
+                    }
+                    // Remove CN line in sdp
+                    sdpLines.splice( i, 1 );
+                }
+            }
+
+            sdpLines[ mLineIndex ] = mLineElements.join( ' ' );
+            return sdpLines;
+        }
+
+        this.extractSdp = function( sdpLine, pattern ) {
+            var result = sdpLine.match( pattern );
+            return ( result && result.length == 2 ) ? result[ 1 ] : null;
+        }    
+
+        // Set the selected codec to the first in m line.
+        this.setDefaultCodec = function( mLine, payload ) {
+            var elements = mLine.split( ' ' );
+            var newLine = new Array();
+            var index = 0;
+            for ( var i = 0; i < elements.length; i++ ) {
+                if ( index === 3 ) // Format of media starts from the fourth.
+                    newLine[ index++ ] = payload; // Put target payload to the first.
+                if ( elements[ i ] !== payload )
+                    newLine[ index++ ] = elements[ i ];
+            }
+            return newLine.join( ' ' );
+        }
+
+    } 
+
+
+
+} );

+ 112 - 177
support/client/lib/vwf/view/webrtc.js

@@ -37,18 +37,6 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
                 "sharing": { audio: true, video: true } 
             };
 
-            // turns on logger debugger console messages 
-            this.debugVwf = {
-                "creation": false,
-                "initializing": false,
-                "parenting": false,
-                "deleting": false,
-                "properties": false,
-                "setting": false,
-                "getting": false,
-                "calling": false
-            };
-
             if ( options === undefined ) { options = {}; }
 
             this.stereo = options.stereo !== undefined  ? options.stereo : false;
@@ -66,10 +54,6 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
         createdNode: function( nodeID, childID, childExtendsID, childImplementsIDs,
             childSource, childType, childIndex, childName, callback /* ( ready ) */ ) {
 
-            if ( this.debugVwf.creation ) {
-                this.kernel.logger.infox( "createdNode", nodeID, childID, childExtendsID, childImplementsIDs, childSource, childType, childName );
-            }
-
             if ( childExtendsID === undefined )
                 return;
 
@@ -139,9 +123,6 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
         initializedNode: function( nodeID, childID, childExtendsID, childImplementsIDs, 
             childSource, childType, childIndex, childName ) {
 
-            if ( this.debugVwf.initializing ) {
-                this.kernel.logger.infox( "initializedNode", nodeID, childID, childExtendsID, childImplementsIDs, childSource, childType, childName );
-            } 
 
             if ( childExtendsID === undefined )
                 return;
@@ -186,9 +167,7 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
 
         deletedNode: function( nodeID ) {
             
-            if ( this.debugVwf.deleting ) {
-                this.kernel.logger.infox( "deletedNode", nodeID );
-            }
+
             // debugger;
 
             //if ( this.kernel.find( nodeID, "parent::element(*,'http://vwf.example.com/clients.vwf')" ).length > 0 ) {
@@ -230,28 +209,19 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
   
         createdProperty: function( nodeID, propertyName, propertyValue ) {
 
-            if ( this.debugVwf.properties ) {
-                this.kernel.logger.infox( "C === createdProperty ", nodeID, propertyName, propertyValue );
-            }
+
 
             this.satProperty( nodeID, propertyName, propertyValue );
         },        
 
         initializedProperty: function( nodeID, propertyName, propertyValue ) {
 
-            if ( this.debugVwf.properties ) {
-                this.kernel.logger.infox( "  I === initializedProperty ", nodeID, propertyName, propertyValue );
-            }
 
             this.satProperty( nodeID, propertyName, propertyValue );
         },        
 
         satProperty: function( nodeID, propertyName, propertyValue ) {
             
-            
-            if ( this.debugVwf.properties || this.debugVwf.setting ) {
-                this.kernel.logger.infox( "    S === satProperty ", nodeID, propertyName, propertyValue );
-            } 
 
             var client = this.state.clients[ nodeID ];
 
@@ -287,12 +257,6 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
                         }
                         break; 
 
-                    case "color":
-                        var clr = new utility.color( propertyValue );
-                        if ( clr ) {
-                            client.color = clr.toString();
-                        }
-                        break;    
 
                     default:  
                         // propertyName is the moniker of the client that 
@@ -311,19 +275,12 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
 
         gotProperty: function( nodeID, propertyName, propertyValue ) {
 
-            if ( this.debugVwf.properties || this.debugVwf.getting ) {
-                this.kernel.logger.infox( "   G === gotProperty ", nodeID, propertyName, propertyValue );
-            }
             var value = undefined;
 
             return value;
         },
 
         calledMethod: function( nodeID, methodName, methodParameters, methodValue ) {
-            
-            if ( this.debugVwf.calling ) {
-                this.kernel.logger.infox( "  CM === calledMethod ", nodeID, methodName, methodParameters );
-            }
 
             switch ( methodName ) {
                 case "setLocalMute":
@@ -349,9 +306,12 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
         
           video.setAttribute('id', id);
           video.setAttribute('autoplay', true);
-          video.setAttribute('src', '');
+          //video.setAttribute('src', '');
           video.setAttribute("webkit-playsinline", true);
           video.setAttribute("controls", true);
+          video.setAttribute("width", 640);
+          video.setAttribute("height", 480);
+          //video.setAttribute("muted", true);
         
           var assets = document.querySelector('a-assets');
         
@@ -391,91 +351,33 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
         return clientNode;
     }
 
-    function displayLocal( stream, name, color ) {
+    function displayLocal( stream, name) {
         var id = this.kernel.moniker();
-        return displayVideo.call( this, id, stream, this.local.url, name, id, true, color );
+        return displayVideo.call( this, id, stream, this.local.url, name, id, true);
     }
 
-    function displayVideo( id, stream, url, name, destMoniker, muted, color ) {
-        
-        var divId = undefined;
-
-        if ( this.videoProperties.create ) {
-            this.videosAdded++
-            var $container;
-            divId = name + this.videosAdded;
-            var videoId = "video-" + divId;
-
-            $container = $( "#" + this.videoElementsDiv );
-            if ( muted ) {
-                $container.append(
-                    "<div id='"+ divId + "'>" +
-                        "<video class='vwf-webrtc-video' id='" + videoId +
-                            "' width='320' height='240' " +
-                            "loop='loop' autoplay muted " +
-                            "style='position: absolute; left: 0; top: 0; z-index: 40;'>" +
-                        "</video>" +
-                    "</div>"
-                );
-
-            } else {
-                $container.append(
-                    "<div id='"+ divId + "'>" +
-                        "<video class='vwf-webrtc-video' id='" + videoId +
-                            "' width='320' height='240'" +
-                            " loop='loop' autoplay " +
-                            "style='position: absolute; left: 0; top: 0; z-index: 40;'>" +
-                        "</video>" +
-                    "</div>"
-                );
-            }
-            
-            var videoE = $( '#'+ videoId )[0];
-            if ( videoE && stream ) {
-                navigator.attachMediaStream( videoE, stream );
-                if ( muted ) {
-                    videoE.muted = true;  // firefox isn't mapping the muted property correctly
-                }
-            }  
-
-            var divEle = $('#'+divId);
-            divEle && divEle.draggable && divEle.draggable();
-           
-        } 
-
-        var clr = new utility.color( color );
-        if ( clr ) { 
-            clr = clr.toArray(); 
-        }
-
-        this.kernel.callMethod( this.kernel.application(), "createVideo", [ {
-            "ID": id,
-            "url": url, 
-            "name": name, 
-            "muted": muted, 
-            "color": clr ? clr : color
-        }, destMoniker ] );       
-        
+    function displayVideo( id, stream, url, name, destMoniker, muted) {
         
         let video = createVideoElementAsAsset(name);
+        //video.setAttribute('src', url);
         video.srcObject = stream;
 
-       this.kernel.callMethod( 'avatar-'+id, "setVideoTexture", [name]);
+        this.kernel.callMethod( 'avatar-'+id, "setVideoTexture", [name]);
 
-        return divId;
+        return id;
     }
 
     function removeVideo( client ) {
         
-        if ( client.videoDivID ) {
-            var $videoWin = $( "#" + client.videoDivID );
-            if ( $videoWin ) {
-                $videoWin.remove();
-            }
-            client.videoDivID = undefined;
-        }
+        // if ( client.videoDivID ) {
+        //     var $videoWin = $( "#" + client.videoDivID );
+        //     if ( $videoWin ) {
+        //         $videoWin.remove();
+        //     }
+        //     client.videoDivID = undefined;
+        // }
 
-        this.kernel.callMethod( this.kernel.application(), "removeVideo", [ client.moniker ] );
+        // this.kernel.callMethod( this.kernel.application(), "removeVideo", [ client.moniker ] );
 
     }
 
@@ -487,31 +389,34 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
 
         if ( this.local.stream === undefined && ( media.video || media.audio ) ) {
             var self = this;
-            var constraints = { 
-                "audio": media.audio, 
-                "video": media.video ? { "mandatory": {}, "optional": [] } : false, 
-            };
-            
-            var successCallback = function( stream ) {
-                self.local.url = URL.createObjectURL( stream );
+
+            var constraints = {
+                audio: true,
+                video: true
+              };
+
+            navigator.mediaDevices.getUserMedia(constraints).then(handleSuccess).catch(handleError);
+
+            function handleError(error) {
+                console.log('navigator.getUserMedia error: ', error);
+              }
+
+            function handleSuccess(stream) {
+                // var videoTracks = stream.getVideoTracks();
+                // console.log('Got stream with constraints:', constraints);
+                // if (videoTracks.length) {
+                //     videoTracks[0].enabled = true;
+                // }
+
+               self.local.url = "url" //URL.createObjectURL( stream );
                 self.local.stream = stream;
 
                 self.kernel.setProperty( self.local.ID, "localUrl", self.local.url );
 
                 var localNode = self.state.clients[ self.local.ID ];
-                displayLocal.call( self, stream, localNode.displayName, localNode.color );
+                displayLocal.call( self, stream, localNode.displayName);
                 sendOffers.call( self );
-            };
-
-            var errorCallback = function( error ) { 
-                console.log("failed to get video stream error: " + error); 
-            };
-
-            try { 
-                navigator.getUserMedia( constraints, successCallback, errorCallback );
-            } catch (e) { 
-                console.log("getUserMedia: error " + e ); 
-            };
+              } 
         }
     }  
 
@@ -671,9 +576,9 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
         this.pc_config = { "iceServers": this.view.iceServers };
         this.pc_constraints = { "optional": [ { "DtlsSrtpKeyAgreement": true } ] };
         // Set up audio and video regardless of what devices are present.
-        this.sdpConstraints = { 'mandatory': {
-                                'OfferToReceiveAudio':true, 
-                                'OfferToReceiveVideo':true }};
+        this.sdpConstraints = {
+                                'offerToReceiveAudio':1, 
+                                'offerToReceiveVideo':1 };
 
         this.connect = function( stream, sendOffer ) {
             var self = this;
@@ -703,7 +608,7 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
                 // }
 
                 try {
-                    this.pc = new RTCPeerConnection( this.pc_config, this.pc_constraints );
+                    this.pc = new RTCPeerConnection( this.pc_config);
                     this.pc.onicecandidate = iceCallback;
 
                     if ( self.view.debug ) console.log("Created RTCPeerConnnection with config \"" + JSON.stringify( this.pc_config ) + "\".");
@@ -718,11 +623,12 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
                     //console.info( "onnegotiationeeded." );
                 }
 
-                this.pc.onaddstream = function( event ) {
+                this.pc.ontrack = function( event ) {
                     if ( self.view.debug ) console.log("Remote stream added.");
                     
-                    self.stream = event.stream;
-                    self.url = URL.createObjectURL( event.stream );
+                    self.stream = event.streams[0];
+
+                    self.url = "url" //URL.createObjectURL( event.streams[0] );
                     
                     if ( self.view.debug ) console.log("Remote stream added.  url: " + self.url );
 
@@ -748,9 +654,20 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
                 }
 
                 if ( stream ) {
-                    if ( this.view.debug ) console.log("Adding local stream.");
+                    
+                    // stream.getVideoTracks();
+                    // stream.getAudioTracks();
+
+                    stream.getTracks().forEach(
+                        function(track) {
+                            self.pc.addTrack(
+                            track,
+                            stream
+                          );
+                        }
+                      );
 
-                    this.pc.addStream( stream );
+                    //this.pc.addStream( stream );
                     this.streamAdded = true;
                 }
 
@@ -791,16 +708,16 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
             if ( this.view.debug ) console.log('S->C: ' +  JSON.stringify(msg) );
             if ( this.pc ) {
                 if ( msg.type === 'offer') {
-                    if ( this.view.stereo ) {
-                        msg.sdp = addStereo( msg.sdp );
-                    }
-                    this.pc.setRemoteDescription( new RTCSessionDescription( msg ) );
+                    // if ( this.view.stereo ) {
+                    //     msg.sdp = addStereo( msg.sdp );
+                    // }
+                    this.pc.setRemoteDescription( new RTCSessionDescription( msg ) ); //msg.sdp
                     this.answer();
                 } else if ( msg.type === 'answer' && this.streamAdded ) {
-                    if ( this.view.stereo ) {
-                        msg.sdp = addStereo( msg.sdp );
-                    }                    
-                    this.pc.setRemoteDescription( new RTCSessionDescription( msg ) );
+                    // if ( this.view.stereo ) {
+                    //     msg.sdp = addStereo( msg.sdp );
+                    // }                    
+                    this.pc.setRemoteDescription( new RTCSessionDescription( msg ) ); //msg.sdp
                 } else if ( msg.type === 'candidate' && this.streamAdded ) {
                     var candidate = new RTCIceCandidate( { 
                         "sdpMLineIndex": msg.label,
@@ -818,43 +735,55 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
             
             var self = this;
             var answerer = function( sessionDescription ) {
-                // Set Opus as the preferred codec in SDP if Opus is present.
-                sessionDescription.sdp = self.preferOpus( sessionDescription.sdp );
-                sessionDescription.sdp = self.setBandwidth( sessionDescription.sdp );
+                // // Set Opus as the preferred codec in SDP if Opus is present.
+                // sessionDescription.sdp = self.preferOpus( sessionDescription.sdp );
+                // sessionDescription.sdp = self.setBandwidth( sessionDescription.sdp );
 
                 self.pc.setLocalDescription( sessionDescription );
-
                 self.view.kernel.setProperty( self.peerNode.ID, self.view.kernel.moniker(), sessionDescription );
             };
 
-            this.pc.createAnswer( answerer, null, this.sdpConstraints);
+            function onCreateSessionDescriptionError(error) {
+                console.log('Failed to create session description: ' + error.toString());
+              }
+
+            this.pc.createAnswer(
+                self.sdpConstraints
+            ).then(
+                answerer,
+                onCreateSessionDescriptionError
+              );
+            //this.pc.createAnswer( answerer, null, this.sdpConstraints);
         };
 
         this.call = function() {
             var self = this;
             var constraints = {
-                "optional": [], 
-                "mandatory": {}
+                offerToReceiveAudio: 1,
+                offerToReceiveVideo: 1
             };
 
-            // temporary measure to remove Moz* constraints in Chrome
-            if ( navigator.webrtcDetectedBrowser === "chrome" ) {
-                for ( var prop in constraints.mandatory ) {
-                    if ( prop.indexOf("Moz") != -1 ) {
-                        delete constraints.mandatory[ prop ];
-                    }
-                }
-            }   
-            constraints = this.mergeConstraints( constraints, this.sdpConstraints );
-
-            if ( this.view.debug ) console.log("Sending offer to peer, with constraints: \n" +  "  \"" + JSON.stringify(constraints) + "\".")
           
             var offerer = function( sessionDescription ) {
-                // Set Opus as the preferred codec in SDP if Opus is present.
-                sessionDescription.sdp = self.preferOpus( sessionDescription.sdp );
 
-                sessionDescription.sdp = self.setBandwidth( sessionDescription.sdp );
-                self.pc.setLocalDescription( sessionDescription );
+                self.pc.setLocalDescription(sessionDescription).then(
+                    function() {
+                      onSetLocalSuccess(self.pc);
+                    },
+                    onSetSessionDescriptionError
+                  );
+
+                  function onSetLocalSuccess(pc) {
+                    console.log(self.pc + ' setLocalDescription complete');
+                  }
+
+                  function onSetSessionDescriptionError(error) {
+                    console.log('Failed to set session description: ' + error.toString());
+                  }
+                // Set Opus as the preferred codec in SDP if Opus is present.
+                // sessionDescription.sdp = self.preferOpus( sessionDescription.sdp );
+                // sessionDescription.sdp = self.setBandwidth( sessionDescription.sdp );
+                // self.pc.setLocalDescription( sessionDescription );
                 
                 //sendSignalMessage.call( sessionDescription, self.peerID );
                 self.view.kernel.setProperty( self.peerNode.ID, self.view.kernel.moniker(), sessionDescription );
@@ -864,7 +793,13 @@ define( [ "module", "vwf/view", "vwf/utility", "vwf/utility/color", "jquery" ],
                 console.log(e)
             }
 
-            this.pc.createOffer( offerer, onFailure, constraints );
+            self.pc.createOffer(
+                constraints
+              ).then(
+                offerer,
+                onFailure
+              );
+            //this.pc.createOffer( offerer, onFailure, constraints );
         };
 
         this.setBandwidth = function( sdp ) {

+ 4471 - 0
support/client/lib/vwf/view/webrtc/dist/adapter-latest.js

@@ -0,0 +1,4471 @@
+(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.adapter = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+
+function writeMediaSection(transceiver, caps, type, stream, dtlsRole) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : dtlsRole || 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+}
+
+// Edge does not like
+// 1) stun: filtered after 14393 unless ?transport=udp is present
+// 2) turn: that does not have all of turn:host:port?transport=udp
+// 3) turn: with ipv6 addresses
+// 4) turn: occurring muliple times
+function filterIceServers(iceServers, edgeVersion) {
+  var hasTurn = false;
+  iceServers = JSON.parse(JSON.stringify(iceServers));
+  return iceServers.filter(function(server) {
+    if (server && (server.urls || server.url)) {
+      var urls = server.urls || server.url;
+      if (server.url && !server.urls) {
+        console.warn('RTCIceServer.url is deprecated! Use urls instead.');
+      }
+      var isString = typeof urls === 'string';
+      if (isString) {
+        urls = [urls];
+      }
+      urls = urls.filter(function(url) {
+        var validTurn = url.indexOf('turn:') === 0 &&
+            url.indexOf('transport=udp') !== -1 &&
+            url.indexOf('turn:[') === -1 &&
+            !hasTurn;
+
+        if (validTurn) {
+          hasTurn = true;
+          return true;
+        }
+        return url.indexOf('stun:') === 0 && edgeVersion >= 14393 &&
+            url.indexOf('?transport=udp') === -1;
+      });
+
+      delete server.url;
+      server.urls = isString ? urls[0] : urls;
+      return !!urls.length;
+    }
+    return false;
+  });
+}
+
+// Determines the intersection of local and remote capabilities.
+function getCommonCapabilities(localCapabilities, remoteCapabilities) {
+  var commonCapabilities = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: []
+  };
+
+  var findCodecByPayloadType = function(pt, codecs) {
+    pt = parseInt(pt, 10);
+    for (var i = 0; i < codecs.length; i++) {
+      if (codecs[i].payloadType === pt ||
+          codecs[i].preferredPayloadType === pt) {
+        return codecs[i];
+      }
+    }
+  };
+
+  var rtxCapabilityMatches = function(lRtx, rRtx, lCodecs, rCodecs) {
+    var lCodec = findCodecByPayloadType(lRtx.parameters.apt, lCodecs);
+    var rCodec = findCodecByPayloadType(rRtx.parameters.apt, rCodecs);
+    return lCodec && rCodec &&
+        lCodec.name.toLowerCase() === rCodec.name.toLowerCase();
+  };
+
+  localCapabilities.codecs.forEach(function(lCodec) {
+    for (var i = 0; i < remoteCapabilities.codecs.length; i++) {
+      var rCodec = remoteCapabilities.codecs[i];
+      if (lCodec.name.toLowerCase() === rCodec.name.toLowerCase() &&
+          lCodec.clockRate === rCodec.clockRate) {
+        if (lCodec.name.toLowerCase() === 'rtx' &&
+            lCodec.parameters && rCodec.parameters.apt) {
+          // for RTX we need to find the local rtx that has a apt
+          // which points to the same local codec as the remote one.
+          if (!rtxCapabilityMatches(lCodec, rCodec,
+              localCapabilities.codecs, remoteCapabilities.codecs)) {
+            continue;
+          }
+        }
+        rCodec = JSON.parse(JSON.stringify(rCodec)); // deepcopy
+        // number of channels is the highest common number of channels
+        rCodec.numChannels = Math.min(lCodec.numChannels,
+            rCodec.numChannels);
+        // push rCodec so we reply with offerer payload type
+        commonCapabilities.codecs.push(rCodec);
+
+        // determine common feedback mechanisms
+        rCodec.rtcpFeedback = rCodec.rtcpFeedback.filter(function(fb) {
+          for (var j = 0; j < lCodec.rtcpFeedback.length; j++) {
+            if (lCodec.rtcpFeedback[j].type === fb.type &&
+                lCodec.rtcpFeedback[j].parameter === fb.parameter) {
+              return true;
+            }
+          }
+          return false;
+        });
+        // FIXME: also need to determine .parameters
+        //  see https://github.com/openpeer/ortc/issues/569
+        break;
+      }
+    }
+  });
+
+  localCapabilities.headerExtensions.forEach(function(lHeaderExtension) {
+    for (var i = 0; i < remoteCapabilities.headerExtensions.length;
+         i++) {
+      var rHeaderExtension = remoteCapabilities.headerExtensions[i];
+      if (lHeaderExtension.uri === rHeaderExtension.uri) {
+        commonCapabilities.headerExtensions.push(rHeaderExtension);
+        break;
+      }
+    }
+  });
+
+  // FIXME: fecMechanisms
+  return commonCapabilities;
+}
+
+// is action=setLocalDescription with type allowed in signalingState
+function isActionAllowedInSignalingState(action, type, signalingState) {
+  return {
+    offer: {
+      setLocalDescription: ['stable', 'have-local-offer'],
+      setRemoteDescription: ['stable', 'have-remote-offer']
+    },
+    answer: {
+      setLocalDescription: ['have-remote-offer', 'have-local-pranswer'],
+      setRemoteDescription: ['have-local-offer', 'have-remote-pranswer']
+    }
+  }[type][action].indexOf(signalingState) !== -1;
+}
+
+function maybeAddCandidate(iceTransport, candidate) {
+  // Edge's internal representation adds some fields therefore
+  // not all fieldѕ are taken into account.
+  var alreadyAdded = iceTransport.getRemoteCandidates()
+      .find(function(remoteCandidate) {
+        return candidate.foundation === remoteCandidate.foundation &&
+            candidate.ip === remoteCandidate.ip &&
+            candidate.port === remoteCandidate.port &&
+            candidate.priority === remoteCandidate.priority &&
+            candidate.protocol === remoteCandidate.protocol &&
+            candidate.type === remoteCandidate.type;
+      });
+  if (!alreadyAdded) {
+    iceTransport.addRemoteCandidate(candidate);
+  }
+  return !alreadyAdded;
+}
+
+module.exports = function(window, edgeVersion) {
+  var RTCPeerConnection = function(config) {
+    var self = this;
+
+    var _eventTarget = document.createDocumentFragment();
+    ['addEventListener', 'removeEventListener', 'dispatchEvent']
+        .forEach(function(method) {
+          self[method] = _eventTarget[method].bind(_eventTarget);
+        });
+
+    this.onicecandidate = null;
+    this.onaddstream = null;
+    this.ontrack = null;
+    this.onremovestream = null;
+    this.onsignalingstatechange = null;
+    this.oniceconnectionstatechange = null;
+    this.onicegatheringstatechange = null;
+    this.onnegotiationneeded = null;
+    this.ondatachannel = null;
+    this.canTrickleIceCandidates = null;
+
+    this.needNegotiation = false;
+
+    this.localStreams = [];
+    this.remoteStreams = [];
+
+    this.localDescription = null;
+    this.remoteDescription = null;
+
+    this.signalingState = 'stable';
+    this.iceConnectionState = 'new';
+    this.iceGatheringState = 'new';
+
+    config = JSON.parse(JSON.stringify(config || {}));
+
+    this.usingBundle = config.bundlePolicy === 'max-bundle';
+    if (config.rtcpMuxPolicy === 'negotiate') {
+      var e = new Error('rtcpMuxPolicy \'negotiate\' is not supported');
+      e.name = 'NotSupportedError';
+      throw(e);
+    } else if (!config.rtcpMuxPolicy) {
+      config.rtcpMuxPolicy = 'require';
+    }
+
+    switch (config.iceTransportPolicy) {
+      case 'all':
+      case 'relay':
+        break;
+      default:
+        config.iceTransportPolicy = 'all';
+        break;
+    }
+
+    switch (config.bundlePolicy) {
+      case 'balanced':
+      case 'max-compat':
+      case 'max-bundle':
+        break;
+      default:
+        config.bundlePolicy = 'balanced';
+        break;
+    }
+
+    config.iceServers = filterIceServers(config.iceServers || [], edgeVersion);
+
+    this._iceGatherers = [];
+    if (config.iceCandidatePoolSize) {
+      for (var i = config.iceCandidatePoolSize; i > 0; i--) {
+        this._iceGatherers = new window.RTCIceGatherer({
+          iceServers: config.iceServers,
+          gatherPolicy: config.iceTransportPolicy
+        });
+      }
+    } else {
+      config.iceCandidatePoolSize = 0;
+    }
+
+    this._config = config;
+
+    // per-track iceGathers, iceTransports, dtlsTransports, rtpSenders, ...
+    // everything that is needed to describe a SDP m-line.
+    this.transceivers = [];
+
+    this._sdpSessionId = SDPUtils.generateSessionId();
+    this._sdpSessionVersion = 0;
+
+    this._dtlsRole = undefined; // role for a=setup to use in answers.
+  };
+
+  RTCPeerConnection.prototype._emitGatheringStateChange = function() {
+    var event = new Event('icegatheringstatechange');
+    this.dispatchEvent(event);
+    if (typeof this.onicegatheringstatechange === 'function') {
+      this.onicegatheringstatechange(event);
+    }
+  };
+
+  RTCPeerConnection.prototype.getConfiguration = function() {
+    return this._config;
+  };
+
+  RTCPeerConnection.prototype.getLocalStreams = function() {
+    return this.localStreams;
+  };
+
+  RTCPeerConnection.prototype.getRemoteStreams = function() {
+    return this.remoteStreams;
+  };
+
+  // internal helper to create a transceiver object.
+  // (whih is not yet the same as the WebRTC 1.0 transceiver)
+  RTCPeerConnection.prototype._createTransceiver = function(kind) {
+    var hasBundleTransport = this.transceivers.length > 0;
+    var transceiver = {
+      track: null,
+      iceGatherer: null,
+      iceTransport: null,
+      dtlsTransport: null,
+      localCapabilities: null,
+      remoteCapabilities: null,
+      rtpSender: null,
+      rtpReceiver: null,
+      kind: kind,
+      mid: null,
+      sendEncodingParameters: null,
+      recvEncodingParameters: null,
+      stream: null,
+      wantReceive: true
+    };
+    if (this.usingBundle && hasBundleTransport) {
+      transceiver.iceTransport = this.transceivers[0].iceTransport;
+      transceiver.dtlsTransport = this.transceivers[0].dtlsTransport;
+    } else {
+      var transports = this._createIceAndDtlsTransports();
+      transceiver.iceTransport = transports.iceTransport;
+      transceiver.dtlsTransport = transports.dtlsTransport;
+    }
+    this.transceivers.push(transceiver);
+    return transceiver;
+  };
+
+  RTCPeerConnection.prototype.addTrack = function(track, stream) {
+    var transceiver;
+    for (var i = 0; i < this.transceivers.length; i++) {
+      if (!this.transceivers[i].track &&
+          this.transceivers[i].kind === track.kind) {
+        transceiver = this.transceivers[i];
+      }
+    }
+    if (!transceiver) {
+      transceiver = this._createTransceiver(track.kind);
+    }
+
+    this._maybeFireNegotiationNeeded();
+
+    if (this.localStreams.indexOf(stream) === -1) {
+      this.localStreams.push(stream);
+    }
+
+    transceiver.track = track;
+    transceiver.stream = stream;
+    transceiver.rtpSender = new window.RTCRtpSender(track,
+        transceiver.dtlsTransport);
+    return transceiver.rtpSender;
+  };
+
+  RTCPeerConnection.prototype.addStream = function(stream) {
+    var self = this;
+    if (edgeVersion >= 15025) {
+      stream.getTracks().forEach(function(track) {
+        self.addTrack(track, stream);
+      });
+    } else {
+      // Clone is necessary for local demos mostly, attaching directly
+      // to two different senders does not work (build 10547).
+      // Fixed in 15025 (or earlier)
+      var clonedStream = stream.clone();
+      stream.getTracks().forEach(function(track, idx) {
+        var clonedTrack = clonedStream.getTracks()[idx];
+        track.addEventListener('enabled', function(event) {
+          clonedTrack.enabled = event.enabled;
+        });
+      });
+      clonedStream.getTracks().forEach(function(track) {
+        self.addTrack(track, clonedStream);
+      });
+    }
+  };
+
+  RTCPeerConnection.prototype.removeStream = function(stream) {
+    var idx = this.localStreams.indexOf(stream);
+    if (idx > -1) {
+      this.localStreams.splice(idx, 1);
+      this._maybeFireNegotiationNeeded();
+    }
+  };
+
+  RTCPeerConnection.prototype.getSenders = function() {
+    return this.transceivers.filter(function(transceiver) {
+      return !!transceiver.rtpSender;
+    })
+    .map(function(transceiver) {
+      return transceiver.rtpSender;
+    });
+  };
+
+  RTCPeerConnection.prototype.getReceivers = function() {
+    return this.transceivers.filter(function(transceiver) {
+      return !!transceiver.rtpReceiver;
+    })
+    .map(function(transceiver) {
+      return transceiver.rtpReceiver;
+    });
+  };
+
+
+  RTCPeerConnection.prototype._createIceGatherer = function(sdpMLineIndex,
+      usingBundle) {
+    var self = this;
+    if (usingBundle && sdpMLineIndex > 0) {
+      return this.transceivers[0].iceGatherer;
+    } else if (this._iceGatherers.length) {
+      return this._iceGatherers.shift();
+    }
+    var iceGatherer = new window.RTCIceGatherer({
+      iceServers: this._config.iceServers,
+      gatherPolicy: this._config.iceTransportPolicy
+    });
+    Object.defineProperty(iceGatherer, 'state',
+        {value: 'new', writable: true}
+    );
+
+    this.transceivers[sdpMLineIndex].candidates = [];
+    this.transceivers[sdpMLineIndex].bufferCandidates = function(event) {
+      var end = !event.candidate || Object.keys(event.candidate).length === 0;
+      // polyfill since RTCIceGatherer.state is not implemented in
+      // Edge 10547 yet.
+      iceGatherer.state = end ? 'completed' : 'gathering';
+      if (self.transceivers[sdpMLineIndex].candidates !== null) {
+        self.transceivers[sdpMLineIndex].candidates.push(event.candidate);
+      }
+    };
+    iceGatherer.addEventListener('localcandidate',
+      this.transceivers[sdpMLineIndex].bufferCandidates);
+    return iceGatherer;
+  };
+
+  // start gathering from an RTCIceGatherer.
+  RTCPeerConnection.prototype._gather = function(mid, sdpMLineIndex) {
+    var self = this;
+    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
+    if (iceGatherer.onlocalcandidate) {
+      return;
+    }
+    var candidates = this.transceivers[sdpMLineIndex].candidates;
+    this.transceivers[sdpMLineIndex].candidates = null;
+    iceGatherer.removeEventListener('localcandidate',
+      this.transceivers[sdpMLineIndex].bufferCandidates);
+    iceGatherer.onlocalcandidate = function(evt) {
+      if (self.usingBundle && sdpMLineIndex > 0) {
+        // if we know that we use bundle we can drop candidates with
+        // ѕdpMLineIndex > 0. If we don't do this then our state gets
+        // confused since we dispose the extra ice gatherer.
+        return;
+      }
+      var event = new Event('icecandidate');
+      event.candidate = {sdpMid: mid, sdpMLineIndex: sdpMLineIndex};
+
+      var cand = evt.candidate;
+      // Edge emits an empty object for RTCIceCandidateComplete‥
+      var end = !cand || Object.keys(cand).length === 0;
+      if (end) {
+        // polyfill since RTCIceGatherer.state is not implemented in
+        // Edge 10547 yet.
+        if (iceGatherer.state === 'new' || iceGatherer.state === 'gathering') {
+          iceGatherer.state = 'completed';
+        }
+      } else {
+        if (iceGatherer.state === 'new') {
+          iceGatherer.state = 'gathering';
+        }
+        // RTCIceCandidate doesn't have a component, needs to be added
+        cand.component = 1;
+        event.candidate.candidate = SDPUtils.writeCandidate(cand);
+      }
+
+      // update local description.
+      var sections = SDPUtils.splitSections(self.localDescription.sdp);
+      if (!end) {
+        sections[event.candidate.sdpMLineIndex + 1] +=
+            'a=' + event.candidate.candidate + '\r\n';
+      } else {
+        sections[event.candidate.sdpMLineIndex + 1] +=
+            'a=end-of-candidates\r\n';
+      }
+      self.localDescription.sdp = sections.join('');
+      var complete = self.transceivers.every(function(transceiver) {
+        return transceiver.iceGatherer &&
+            transceiver.iceGatherer.state === 'completed';
+      });
+
+      if (self.iceGatheringState !== 'gathering') {
+        self.iceGatheringState = 'gathering';
+        self._emitGatheringStateChange();
+      }
+
+      // Emit candidate. Also emit null candidate when all gatherers are
+      // complete.
+      if (!end) {
+        self.dispatchEvent(event);
+        if (typeof self.onicecandidate === 'function') {
+          self.onicecandidate(event);
+        }
+      }
+      if (complete) {
+        self.dispatchEvent(new Event('icecandidate'));
+        if (typeof self.onicecandidate === 'function') {
+          self.onicecandidate(new Event('icecandidate'));
+        }
+        self.iceGatheringState = 'complete';
+        self._emitGatheringStateChange();
+      }
+    };
+
+    // emit already gathered candidates.
+    window.setTimeout(function() {
+      candidates.forEach(function(candidate) {
+        var e = new Event('RTCIceGatherEvent');
+        e.candidate = candidate;
+        iceGatherer.onlocalcandidate(e);
+      });
+    }, 0);
+  };
+
+  // Create ICE transport and DTLS transport.
+  RTCPeerConnection.prototype._createIceAndDtlsTransports = function() {
+    var self = this;
+    var iceTransport = new window.RTCIceTransport(null);
+    iceTransport.onicestatechange = function() {
+      self._updateConnectionState();
+    };
+
+    var dtlsTransport = new window.RTCDtlsTransport(iceTransport);
+    dtlsTransport.ondtlsstatechange = function() {
+      self._updateConnectionState();
+    };
+    dtlsTransport.onerror = function() {
+      // onerror does not set state to failed by itself.
+      Object.defineProperty(dtlsTransport, 'state',
+          {value: 'failed', writable: true});
+      self._updateConnectionState();
+    };
+
+    return {
+      iceTransport: iceTransport,
+      dtlsTransport: dtlsTransport
+    };
+  };
+
+  // Destroy ICE gatherer, ICE transport and DTLS transport.
+  // Without triggering the callbacks.
+  RTCPeerConnection.prototype._disposeIceAndDtlsTransports = function(
+      sdpMLineIndex) {
+    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
+    if (iceGatherer) {
+      delete iceGatherer.onlocalcandidate;
+      delete this.transceivers[sdpMLineIndex].iceGatherer;
+    }
+    var iceTransport = this.transceivers[sdpMLineIndex].iceTransport;
+    if (iceTransport) {
+      delete iceTransport.onicestatechange;
+      delete this.transceivers[sdpMLineIndex].iceTransport;
+    }
+    var dtlsTransport = this.transceivers[sdpMLineIndex].dtlsTransport;
+    if (dtlsTransport) {
+      delete dtlsTransport.ondtlsstatechange;
+      delete dtlsTransport.onerror;
+      delete this.transceivers[sdpMLineIndex].dtlsTransport;
+    }
+  };
+
+  // Start the RTP Sender and Receiver for a transceiver.
+  RTCPeerConnection.prototype._transceive = function(transceiver,
+      send, recv) {
+    var params = getCommonCapabilities(transceiver.localCapabilities,
+        transceiver.remoteCapabilities);
+    if (send && transceiver.rtpSender) {
+      params.encodings = transceiver.sendEncodingParameters;
+      params.rtcp = {
+        cname: SDPUtils.localCName,
+        compound: transceiver.rtcpParameters.compound
+      };
+      if (transceiver.recvEncodingParameters.length) {
+        params.rtcp.ssrc = transceiver.recvEncodingParameters[0].ssrc;
+      }
+      transceiver.rtpSender.send(params);
+    }
+    if (recv && transceiver.rtpReceiver && params.codecs.length > 0) {
+      // remove RTX field in Edge 14942
+      if (transceiver.kind === 'video'
+          && transceiver.recvEncodingParameters
+          && edgeVersion < 15019) {
+        transceiver.recvEncodingParameters.forEach(function(p) {
+          delete p.rtx;
+        });
+      }
+      params.encodings = transceiver.recvEncodingParameters;
+      params.rtcp = {
+        cname: transceiver.rtcpParameters.cname,
+        compound: transceiver.rtcpParameters.compound
+      };
+      if (transceiver.sendEncodingParameters.length) {
+        params.rtcp.ssrc = transceiver.sendEncodingParameters[0].ssrc;
+      }
+      transceiver.rtpReceiver.receive(params);
+    }
+  };
+
+  RTCPeerConnection.prototype.setLocalDescription = function(description) {
+    var self = this;
+    var args = arguments;
+
+    if (!isActionAllowedInSignalingState('setLocalDescription',
+        description.type, this.signalingState)) {
+      return new Promise(function(resolve, reject) {
+        var e = new Error('Can not set local ' + description.type +
+            ' in state ' + self.signalingState);
+        e.name = 'InvalidStateError';
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [e]);
+        }
+        reject(e);
+      });
+    }
+
+    var sections;
+    var sessionpart;
+    if (description.type === 'offer') {
+      // VERY limited support for SDP munging. Limited to:
+      // * changing the order of codecs
+      sections = SDPUtils.splitSections(description.sdp);
+      sessionpart = sections.shift();
+      sections.forEach(function(mediaSection, sdpMLineIndex) {
+        var caps = SDPUtils.parseRtpParameters(mediaSection);
+        self.transceivers[sdpMLineIndex].localCapabilities = caps;
+      });
+
+      this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+        self._gather(transceiver.mid, sdpMLineIndex);
+      });
+    } else if (description.type === 'answer') {
+      sections = SDPUtils.splitSections(self.remoteDescription.sdp);
+      sessionpart = sections.shift();
+      var isIceLite = SDPUtils.matchPrefix(sessionpart,
+          'a=ice-lite').length > 0;
+      sections.forEach(function(mediaSection, sdpMLineIndex) {
+        var transceiver = self.transceivers[sdpMLineIndex];
+        var iceGatherer = transceiver.iceGatherer;
+        var iceTransport = transceiver.iceTransport;
+        var dtlsTransport = transceiver.dtlsTransport;
+        var localCapabilities = transceiver.localCapabilities;
+        var remoteCapabilities = transceiver.remoteCapabilities;
+
+        // treat bundle-only as not-rejected.
+        var rejected = SDPUtils.isRejected(mediaSection) &&
+            !SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 1;
+
+        if (!rejected && !transceiver.isDatachannel) {
+          var remoteIceParameters = SDPUtils.getIceParameters(
+              mediaSection, sessionpart);
+          var remoteDtlsParameters = SDPUtils.getDtlsParameters(
+              mediaSection, sessionpart);
+          if (isIceLite) {
+            remoteDtlsParameters.role = 'server';
+          }
+
+          if (!self.usingBundle || sdpMLineIndex === 0) {
+            self._gather(transceiver.mid, sdpMLineIndex);
+            if (iceTransport.state === 'new') {
+              iceTransport.start(iceGatherer, remoteIceParameters,
+                  isIceLite ? 'controlling' : 'controlled');
+            }
+            if (dtlsTransport.state === 'new') {
+              dtlsTransport.start(remoteDtlsParameters);
+            }
+          }
+
+          // Calculate intersection of capabilities.
+          var params = getCommonCapabilities(localCapabilities,
+              remoteCapabilities);
+
+          // Start the RTCRtpSender. The RTCRtpReceiver for this
+          // transceiver has already been started in setRemoteDescription.
+          self._transceive(transceiver,
+              params.codecs.length > 0,
+              false);
+        }
+      });
+    }
+
+    this.localDescription = {
+      type: description.type,
+      sdp: description.sdp
+    };
+    switch (description.type) {
+      case 'offer':
+        this._updateSignalingState('have-local-offer');
+        break;
+      case 'answer':
+        this._updateSignalingState('stable');
+        break;
+      default:
+        throw new TypeError('unsupported type "' + description.type +
+            '"');
+    }
+
+    // If a success callback was provided, emit ICE candidates after it
+    // has been executed. Otherwise, emit callback after the Promise is
+    // resolved.
+    var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
+        arguments[1];
+    return new Promise(function(resolve) {
+      if (cb) {
+        cb.apply(null);
+      }
+      resolve();
+    });
+  };
+
+  RTCPeerConnection.prototype.setRemoteDescription = function(description) {
+    var self = this;
+    var args = arguments;
+
+    if (!isActionAllowedInSignalingState('setRemoteDescription',
+        description.type, this.signalingState)) {
+      return new Promise(function(resolve, reject) {
+        var e = new Error('Can not set remote ' + description.type +
+            ' in state ' + self.signalingState);
+        e.name = 'InvalidStateError';
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [e]);
+        }
+        reject(e);
+      });
+    }
+
+    var streams = {};
+    this.remoteStreams.forEach(function(stream) {
+      streams[stream.id] = stream;
+    });
+    var receiverList = [];
+    var sections = SDPUtils.splitSections(description.sdp);
+    var sessionpart = sections.shift();
+    var isIceLite = SDPUtils.matchPrefix(sessionpart,
+        'a=ice-lite').length > 0;
+    var usingBundle = SDPUtils.matchPrefix(sessionpart,
+        'a=group:BUNDLE ').length > 0;
+    this.usingBundle = usingBundle;
+    var iceOptions = SDPUtils.matchPrefix(sessionpart,
+        'a=ice-options:')[0];
+    if (iceOptions) {
+      this.canTrickleIceCandidates = iceOptions.substr(14).split(' ')
+          .indexOf('trickle') >= 0;
+    } else {
+      this.canTrickleIceCandidates = false;
+    }
+
+    sections.forEach(function(mediaSection, sdpMLineIndex) {
+      var lines = SDPUtils.splitLines(mediaSection);
+      var kind = SDPUtils.getKind(mediaSection);
+      // treat bundle-only as not-rejected.
+      var rejected = SDPUtils.isRejected(mediaSection) &&
+          !SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 1;
+      var protocol = lines[0].substr(2).split(' ')[2];
+
+      var direction = SDPUtils.getDirection(mediaSection, sessionpart);
+      var remoteMsid = SDPUtils.parseMsid(mediaSection);
+
+      var mid = SDPUtils.getMid(mediaSection) || SDPUtils.generateIdentifier();
+
+      // Reject datachannels which are not implemented yet.
+      if (kind === 'application' && protocol === 'DTLS/SCTP') {
+        self.transceivers[sdpMLineIndex] = {
+          mid: mid,
+          isDatachannel: true
+        };
+        return;
+      }
+
+      var transceiver;
+      var iceGatherer;
+      var iceTransport;
+      var dtlsTransport;
+      var rtpReceiver;
+      var sendEncodingParameters;
+      var recvEncodingParameters;
+      var localCapabilities;
+
+      var track;
+      // FIXME: ensure the mediaSection has rtcp-mux set.
+      var remoteCapabilities = SDPUtils.parseRtpParameters(mediaSection);
+      var remoteIceParameters;
+      var remoteDtlsParameters;
+      if (!rejected) {
+        remoteIceParameters = SDPUtils.getIceParameters(mediaSection,
+            sessionpart);
+        remoteDtlsParameters = SDPUtils.getDtlsParameters(mediaSection,
+            sessionpart);
+        remoteDtlsParameters.role = 'client';
+      }
+      recvEncodingParameters =
+          SDPUtils.parseRtpEncodingParameters(mediaSection);
+
+      var rtcpParameters = SDPUtils.parseRtcpParameters(mediaSection);
+
+      var isComplete = SDPUtils.matchPrefix(mediaSection,
+          'a=end-of-candidates', sessionpart).length > 0;
+      var cands = SDPUtils.matchPrefix(mediaSection, 'a=candidate:')
+          .map(function(cand) {
+            return SDPUtils.parseCandidate(cand);
+          })
+          .filter(function(cand) {
+            return cand.component === 1;
+          });
+
+      // Check if we can use BUNDLE and dispose transports.
+      if ((description.type === 'offer' || description.type === 'answer') &&
+          !rejected && usingBundle && sdpMLineIndex > 0 &&
+          self.transceivers[sdpMLineIndex]) {
+        self._disposeIceAndDtlsTransports(sdpMLineIndex);
+        self.transceivers[sdpMLineIndex].iceGatherer =
+            self.transceivers[0].iceGatherer;
+        self.transceivers[sdpMLineIndex].iceTransport =
+            self.transceivers[0].iceTransport;
+        self.transceivers[sdpMLineIndex].dtlsTransport =
+            self.transceivers[0].dtlsTransport;
+        if (self.transceivers[sdpMLineIndex].rtpSender) {
+          self.transceivers[sdpMLineIndex].rtpSender.setTransport(
+              self.transceivers[0].dtlsTransport);
+        }
+        if (self.transceivers[sdpMLineIndex].rtpReceiver) {
+          self.transceivers[sdpMLineIndex].rtpReceiver.setTransport(
+              self.transceivers[0].dtlsTransport);
+        }
+      }
+      if (description.type === 'offer' && !rejected) {
+        transceiver = self.transceivers[sdpMLineIndex] ||
+            self._createTransceiver(kind);
+        transceiver.mid = mid;
+
+        if (!transceiver.iceGatherer) {
+          transceiver.iceGatherer = self._createIceGatherer(sdpMLineIndex,
+              usingBundle);
+        }
+
+        if (cands.length && transceiver.iceTransport.state === 'new') {
+          if (isComplete && (!usingBundle || sdpMLineIndex === 0)) {
+            transceiver.iceTransport.setRemoteCandidates(cands);
+          } else {
+            cands.forEach(function(candidate) {
+              maybeAddCandidate(transceiver.iceTransport, candidate);
+            });
+          }
+        }
+
+        localCapabilities = window.RTCRtpReceiver.getCapabilities(kind);
+
+        // filter RTX until additional stuff needed for RTX is implemented
+        // in adapter.js
+        if (edgeVersion < 15019) {
+          localCapabilities.codecs = localCapabilities.codecs.filter(
+              function(codec) {
+                return codec.name !== 'rtx';
+              });
+        }
+
+        sendEncodingParameters = transceiver.sendEncodingParameters || [{
+          ssrc: (2 * sdpMLineIndex + 2) * 1001
+        }];
+
+        var isNewTrack = false;
+        if (direction === 'sendrecv' || direction === 'sendonly') {
+          isNewTrack = !transceiver.rtpReceiver;
+          rtpReceiver = transceiver.rtpReceiver ||
+              new window.RTCRtpReceiver(transceiver.dtlsTransport, kind);
+
+          if (isNewTrack) {
+            var stream;
+            track = rtpReceiver.track;
+            // FIXME: does not work with Plan B.
+            if (remoteMsid) {
+              if (!streams[remoteMsid.stream]) {
+                streams[remoteMsid.stream] = new window.MediaStream();
+                Object.defineProperty(streams[remoteMsid.stream], 'id', {
+                  get: function() {
+                    return remoteMsid.stream;
+                  }
+                });
+              }
+              Object.defineProperty(track, 'id', {
+                get: function() {
+                  return remoteMsid.track;
+                }
+              });
+              stream = streams[remoteMsid.stream];
+            } else {
+              if (!streams.default) {
+                streams.default = new window.MediaStream();
+              }
+              stream = streams.default;
+            }
+            stream.addTrack(track);
+            receiverList.push([track, rtpReceiver, stream]);
+          }
+        }
+
+        transceiver.localCapabilities = localCapabilities;
+        transceiver.remoteCapabilities = remoteCapabilities;
+        transceiver.rtpReceiver = rtpReceiver;
+        transceiver.rtcpParameters = rtcpParameters;
+        transceiver.sendEncodingParameters = sendEncodingParameters;
+        transceiver.recvEncodingParameters = recvEncodingParameters;
+
+        // Start the RTCRtpReceiver now. The RTPSender is started in
+        // setLocalDescription.
+        self._transceive(self.transceivers[sdpMLineIndex],
+            false,
+            isNewTrack);
+      } else if (description.type === 'answer' && !rejected) {
+        transceiver = self.transceivers[sdpMLineIndex];
+        iceGatherer = transceiver.iceGatherer;
+        iceTransport = transceiver.iceTransport;
+        dtlsTransport = transceiver.dtlsTransport;
+        rtpReceiver = transceiver.rtpReceiver;
+        sendEncodingParameters = transceiver.sendEncodingParameters;
+        localCapabilities = transceiver.localCapabilities;
+
+        self.transceivers[sdpMLineIndex].recvEncodingParameters =
+            recvEncodingParameters;
+        self.transceivers[sdpMLineIndex].remoteCapabilities =
+            remoteCapabilities;
+        self.transceivers[sdpMLineIndex].rtcpParameters = rtcpParameters;
+
+        if (cands.length && iceTransport.state === 'new') {
+          if ((isIceLite || isComplete) &&
+              (!usingBundle || sdpMLineIndex === 0)) {
+            iceTransport.setRemoteCandidates(cands);
+          } else {
+            cands.forEach(function(candidate) {
+              maybeAddCandidate(transceiver.iceTransport, candidate);
+            });
+          }
+        }
+
+        if (!usingBundle || sdpMLineIndex === 0) {
+          if (iceTransport.state === 'new') {
+            iceTransport.start(iceGatherer, remoteIceParameters,
+                'controlling');
+          }
+          if (dtlsTransport.state === 'new') {
+            dtlsTransport.start(remoteDtlsParameters);
+          }
+        }
+
+        self._transceive(transceiver,
+            direction === 'sendrecv' || direction === 'recvonly',
+            direction === 'sendrecv' || direction === 'sendonly');
+
+        if (rtpReceiver &&
+            (direction === 'sendrecv' || direction === 'sendonly')) {
+          track = rtpReceiver.track;
+          if (remoteMsid) {
+            if (!streams[remoteMsid.stream]) {
+              streams[remoteMsid.stream] = new window.MediaStream();
+            }
+            streams[remoteMsid.stream].addTrack(track);
+            receiverList.push([track, rtpReceiver, streams[remoteMsid.stream]]);
+          } else {
+            if (!streams.default) {
+              streams.default = new window.MediaStream();
+            }
+            streams.default.addTrack(track);
+            receiverList.push([track, rtpReceiver, streams.default]);
+          }
+        } else {
+          // FIXME: actually the receiver should be created later.
+          delete transceiver.rtpReceiver;
+        }
+      }
+    });
+
+    if (this._dtlsRole === undefined) {
+      this._dtlsRole = description.type === 'offer' ? 'active' : 'passive';
+    }
+
+    this.remoteDescription = {
+      type: description.type,
+      sdp: description.sdp
+    };
+    switch (description.type) {
+      case 'offer':
+        this._updateSignalingState('have-remote-offer');
+        break;
+      case 'answer':
+        this._updateSignalingState('stable');
+        break;
+      default:
+        throw new TypeError('unsupported type "' + description.type +
+            '"');
+    }
+    Object.keys(streams).forEach(function(sid) {
+      var stream = streams[sid];
+      if (stream.getTracks().length) {
+        if (self.remoteStreams.indexOf(stream) === -1) {
+          self.remoteStreams.push(stream);
+          var event = new Event('addstream');
+          event.stream = stream;
+          window.setTimeout(function() {
+            self.dispatchEvent(event);
+            if (typeof self.onaddstream === 'function') {
+              self.onaddstream(event);
+            }
+          });
+        }
+
+        receiverList.forEach(function(item) {
+          var track = item[0];
+          var receiver = item[1];
+          if (stream.id !== item[2].id) {
+            return;
+          }
+          var trackEvent = new Event('track');
+          trackEvent.track = track;
+          trackEvent.receiver = receiver;
+          trackEvent.transceiver = {receiver: receiver};
+          trackEvent.streams = [stream];
+          window.setTimeout(function() {
+            self.dispatchEvent(trackEvent);
+            if (typeof self.ontrack === 'function') {
+              self.ontrack(trackEvent);
+            }
+          });
+        });
+      }
+    });
+
+    // check whether addIceCandidate({}) was called within four seconds after
+    // setRemoteDescription.
+    window.setTimeout(function() {
+      if (!(self && self.transceivers)) {
+        return;
+      }
+      self.transceivers.forEach(function(transceiver) {
+        if (transceiver.iceTransport &&
+            transceiver.iceTransport.state === 'new' &&
+            transceiver.iceTransport.getRemoteCandidates().length > 0) {
+          console.warn('Timeout for addRemoteCandidate. Consider sending ' +
+              'an end-of-candidates notification');
+          transceiver.iceTransport.addRemoteCandidate({});
+        }
+      });
+    }, 4000);
+
+    return new Promise(function(resolve) {
+      if (args.length > 1 && typeof args[1] === 'function') {
+        args[1].apply(null);
+      }
+      resolve();
+    });
+  };
+
+  RTCPeerConnection.prototype.close = function() {
+    this.transceivers.forEach(function(transceiver) {
+      /* not yet
+      if (transceiver.iceGatherer) {
+        transceiver.iceGatherer.close();
+      }
+      */
+      if (transceiver.iceTransport) {
+        transceiver.iceTransport.stop();
+      }
+      if (transceiver.dtlsTransport) {
+        transceiver.dtlsTransport.stop();
+      }
+      if (transceiver.rtpSender) {
+        transceiver.rtpSender.stop();
+      }
+      if (transceiver.rtpReceiver) {
+        transceiver.rtpReceiver.stop();
+      }
+    });
+    // FIXME: clean up tracks, local streams, remote streams, etc
+    this._updateSignalingState('closed');
+  };
+
+  // Update the signaling state.
+  RTCPeerConnection.prototype._updateSignalingState = function(newState) {
+    this.signalingState = newState;
+    var event = new Event('signalingstatechange');
+    this.dispatchEvent(event);
+    if (typeof this.onsignalingstatechange === 'function') {
+      this.onsignalingstatechange(event);
+    }
+  };
+
+  // Determine whether to fire the negotiationneeded event.
+  RTCPeerConnection.prototype._maybeFireNegotiationNeeded = function() {
+    var self = this;
+    if (this.signalingState !== 'stable' || this.needNegotiation === true) {
+      return;
+    }
+    this.needNegotiation = true;
+    window.setTimeout(function() {
+      if (self.needNegotiation === false) {
+        return;
+      }
+      self.needNegotiation = false;
+      var event = new Event('negotiationneeded');
+      self.dispatchEvent(event);
+      if (typeof self.onnegotiationneeded === 'function') {
+        self.onnegotiationneeded(event);
+      }
+    }, 0);
+  };
+
+  // Update the connection state.
+  RTCPeerConnection.prototype._updateConnectionState = function() {
+    var newState;
+    var states = {
+      'new': 0,
+      closed: 0,
+      connecting: 0,
+      checking: 0,
+      connected: 0,
+      completed: 0,
+      disconnected: 0,
+      failed: 0
+    };
+    this.transceivers.forEach(function(transceiver) {
+      states[transceiver.iceTransport.state]++;
+      states[transceiver.dtlsTransport.state]++;
+    });
+    // ICETransport.completed and connected are the same for this purpose.
+    states.connected += states.completed;
+
+    newState = 'new';
+    if (states.failed > 0) {
+      newState = 'failed';
+    } else if (states.connecting > 0 || states.checking > 0) {
+      newState = 'connecting';
+    } else if (states.disconnected > 0) {
+      newState = 'disconnected';
+    } else if (states.new > 0) {
+      newState = 'new';
+    } else if (states.connected > 0 || states.completed > 0) {
+      newState = 'connected';
+    }
+
+    if (newState !== this.iceConnectionState) {
+      this.iceConnectionState = newState;
+      var event = new Event('iceconnectionstatechange');
+      this.dispatchEvent(event);
+      if (typeof this.oniceconnectionstatechange === 'function') {
+        this.oniceconnectionstatechange(event);
+      }
+    }
+  };
+
+  RTCPeerConnection.prototype.createOffer = function() {
+    var self = this;
+    var args = arguments;
+
+    var offerOptions;
+    if (arguments.length === 1 && typeof arguments[0] !== 'function') {
+      offerOptions = arguments[0];
+    } else if (arguments.length === 3) {
+      offerOptions = arguments[2];
+    }
+
+    var numAudioTracks = this.transceivers.filter(function(t) {
+      return t.kind === 'audio';
+    }).length;
+    var numVideoTracks = this.transceivers.filter(function(t) {
+      return t.kind === 'video';
+    }).length;
+
+    // Determine number of audio and video tracks we need to send/recv.
+    if (offerOptions) {
+      // Reject Chrome legacy constraints.
+      if (offerOptions.mandatory || offerOptions.optional) {
+        throw new TypeError(
+            'Legacy mandatory/optional constraints not supported.');
+      }
+      if (offerOptions.offerToReceiveAudio !== undefined) {
+        if (offerOptions.offerToReceiveAudio === true) {
+          numAudioTracks = 1;
+        } else if (offerOptions.offerToReceiveAudio === false) {
+          numAudioTracks = 0;
+        } else {
+          numAudioTracks = offerOptions.offerToReceiveAudio;
+        }
+      }
+      if (offerOptions.offerToReceiveVideo !== undefined) {
+        if (offerOptions.offerToReceiveVideo === true) {
+          numVideoTracks = 1;
+        } else if (offerOptions.offerToReceiveVideo === false) {
+          numVideoTracks = 0;
+        } else {
+          numVideoTracks = offerOptions.offerToReceiveVideo;
+        }
+      }
+    }
+
+    this.transceivers.forEach(function(transceiver) {
+      if (transceiver.kind === 'audio') {
+        numAudioTracks--;
+        if (numAudioTracks < 0) {
+          transceiver.wantReceive = false;
+        }
+      } else if (transceiver.kind === 'video') {
+        numVideoTracks--;
+        if (numVideoTracks < 0) {
+          transceiver.wantReceive = false;
+        }
+      }
+    });
+
+    // Create M-lines for recvonly streams.
+    while (numAudioTracks > 0 || numVideoTracks > 0) {
+      if (numAudioTracks > 0) {
+        this._createTransceiver('audio');
+        numAudioTracks--;
+      }
+      if (numVideoTracks > 0) {
+        this._createTransceiver('video');
+        numVideoTracks--;
+      }
+    }
+
+    var sdp = SDPUtils.writeSessionBoilerplate(this._sdpSessionId,
+        this._sdpSessionVersion++);
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      // For each track, create an ice gatherer, ice transport,
+      // dtls transport, potentially rtpsender and rtpreceiver.
+      var track = transceiver.track;
+      var kind = transceiver.kind;
+      var mid = SDPUtils.generateIdentifier();
+      transceiver.mid = mid;
+
+      if (!transceiver.iceGatherer) {
+        transceiver.iceGatherer = self._createIceGatherer(sdpMLineIndex,
+            self.usingBundle);
+      }
+
+      var localCapabilities = window.RTCRtpSender.getCapabilities(kind);
+      // filter RTX until additional stuff needed for RTX is implemented
+      // in adapter.js
+      if (edgeVersion < 15019) {
+        localCapabilities.codecs = localCapabilities.codecs.filter(
+            function(codec) {
+              return codec.name !== 'rtx';
+            });
+      }
+      localCapabilities.codecs.forEach(function(codec) {
+        // work around https://bugs.chromium.org/p/webrtc/issues/detail?id=6552
+        // by adding level-asymmetry-allowed=1
+        if (codec.name === 'H264' &&
+            codec.parameters['level-asymmetry-allowed'] === undefined) {
+          codec.parameters['level-asymmetry-allowed'] = '1';
+        }
+      });
+
+      // generate an ssrc now, to be used later in rtpSender.send
+      var sendEncodingParameters = transceiver.sendEncodingParameters || [{
+        ssrc: (2 * sdpMLineIndex + 1) * 1001
+      }];
+      if (track) {
+        // add RTX
+        if (edgeVersion >= 15019 && kind === 'video' &&
+            !sendEncodingParameters[0].rtx) {
+          sendEncodingParameters[0].rtx = {
+            ssrc: sendEncodingParameters[0].ssrc + 1
+          };
+        }
+      }
+
+      if (transceiver.wantReceive) {
+        transceiver.rtpReceiver = new window.RTCRtpReceiver(
+            transceiver.dtlsTransport, kind);
+      }
+
+      transceiver.localCapabilities = localCapabilities;
+      transceiver.sendEncodingParameters = sendEncodingParameters;
+    });
+
+    // always offer BUNDLE and dispose on return if not supported.
+    if (this._config.bundlePolicy !== 'max-compat') {
+      sdp += 'a=group:BUNDLE ' + this.transceivers.map(function(t) {
+        return t.mid;
+      }).join(' ') + '\r\n';
+    }
+    sdp += 'a=ice-options:trickle\r\n';
+
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      sdp += writeMediaSection(transceiver, transceiver.localCapabilities,
+          'offer', transceiver.stream, self._dtlsRole);
+      sdp += 'a=rtcp-rsize\r\n';
+
+      if (transceiver.iceGatherer && self.iceGatheringState !== 'new' &&
+          (sdpMLineIndex === 0 || !self.usingBundle)) {
+        transceiver.iceGatherer.getLocalCandidates().forEach(function(cand) {
+          cand.component = 1;
+          sdp += 'a=' + SDPUtils.writeCandidate(cand) + '\r\n';
+        });
+
+        if (transceiver.iceGatherer.state === 'completed') {
+          sdp += 'a=end-of-candidates\r\n';
+        }
+      }
+    });
+
+    var desc = new window.RTCSessionDescription({
+      type: 'offer',
+      sdp: sdp
+    });
+    return new Promise(function(resolve) {
+      if (args.length > 0 && typeof args[0] === 'function') {
+        args[0].apply(null, [desc]);
+        resolve();
+        return;
+      }
+      resolve(desc);
+    });
+  };
+
+  RTCPeerConnection.prototype.createAnswer = function() {
+    var self = this;
+    var args = arguments;
+
+    var sdp = SDPUtils.writeSessionBoilerplate(this._sdpSessionId,
+        this._sdpSessionVersion++);
+    if (this.usingBundle) {
+      sdp += 'a=group:BUNDLE ' + this.transceivers.map(function(t) {
+        return t.mid;
+      }).join(' ') + '\r\n';
+    }
+    var mediaSectionsInOffer = SDPUtils.splitSections(
+        this.remoteDescription.sdp).length - 1;
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      if (sdpMLineIndex + 1 > mediaSectionsInOffer) {
+        return;
+      }
+      if (transceiver.isDatachannel) {
+        sdp += 'm=application 0 DTLS/SCTP 5000\r\n' +
+            'c=IN IP4 0.0.0.0\r\n' +
+            'a=mid:' + transceiver.mid + '\r\n';
+        return;
+      }
+
+      // FIXME: look at direction.
+      if (transceiver.stream) {
+        var localTrack;
+        if (transceiver.kind === 'audio') {
+          localTrack = transceiver.stream.getAudioTracks()[0];
+        } else if (transceiver.kind === 'video') {
+          localTrack = transceiver.stream.getVideoTracks()[0];
+        }
+        if (localTrack) {
+          // add RTX
+          if (edgeVersion >= 15019 && transceiver.kind === 'video' &&
+              !transceiver.sendEncodingParameters[0].rtx) {
+            transceiver.sendEncodingParameters[0].rtx = {
+              ssrc: transceiver.sendEncodingParameters[0].ssrc + 1
+            };
+          }
+        }
+      }
+
+      // Calculate intersection of capabilities.
+      var commonCapabilities = getCommonCapabilities(
+          transceiver.localCapabilities,
+          transceiver.remoteCapabilities);
+
+      var hasRtx = commonCapabilities.codecs.filter(function(c) {
+        return c.name.toLowerCase() === 'rtx';
+      }).length;
+      if (!hasRtx && transceiver.sendEncodingParameters[0].rtx) {
+        delete transceiver.sendEncodingParameters[0].rtx;
+      }
+
+      sdp += writeMediaSection(transceiver, commonCapabilities,
+          'answer', transceiver.stream, self._dtlsRole);
+      if (transceiver.rtcpParameters &&
+          transceiver.rtcpParameters.reducedSize) {
+        sdp += 'a=rtcp-rsize\r\n';
+      }
+    });
+
+    var desc = new window.RTCSessionDescription({
+      type: 'answer',
+      sdp: sdp
+    });
+    return new Promise(function(resolve) {
+      if (args.length > 0 && typeof args[0] === 'function') {
+        args[0].apply(null, [desc]);
+        resolve();
+        return;
+      }
+      resolve(desc);
+    });
+  };
+
+  RTCPeerConnection.prototype.addIceCandidate = function(candidate) {
+    var err;
+    var sections;
+    if (!candidate || candidate.candidate === '') {
+      for (var j = 0; j < this.transceivers.length; j++) {
+        if (this.transceivers[j].isDatachannel) {
+          continue;
+        }
+        this.transceivers[j].iceTransport.addRemoteCandidate({});
+        sections = SDPUtils.splitSections(this.remoteDescription.sdp);
+        sections[j + 1] += 'a=end-of-candidates\r\n';
+        this.remoteDescription.sdp = sections.join('');
+        if (this.usingBundle) {
+          break;
+        }
+      }
+    } else if (!(candidate.sdpMLineIndex !== undefined || candidate.sdpMid)) {
+      throw new TypeError('sdpMLineIndex or sdpMid required');
+    } else if (!this.remoteDescription) {
+      err = new Error('Can not add ICE candidate without ' +
+          'a remote description');
+      err.name = 'InvalidStateError';
+    } else {
+      var sdpMLineIndex = candidate.sdpMLineIndex;
+      if (candidate.sdpMid) {
+        for (var i = 0; i < this.transceivers.length; i++) {
+          if (this.transceivers[i].mid === candidate.sdpMid) {
+            sdpMLineIndex = i;
+            break;
+          }
+        }
+      }
+      var transceiver = this.transceivers[sdpMLineIndex];
+      if (transceiver) {
+        if (transceiver.isDatachannel) {
+          return Promise.resolve();
+        }
+        var cand = Object.keys(candidate.candidate).length > 0 ?
+            SDPUtils.parseCandidate(candidate.candidate) : {};
+        // Ignore Chrome's invalid candidates since Edge does not like them.
+        if (cand.protocol === 'tcp' && (cand.port === 0 || cand.port === 9)) {
+          return Promise.resolve();
+        }
+        // Ignore RTCP candidates, we assume RTCP-MUX.
+        if (cand.component && cand.component !== 1) {
+          return Promise.resolve();
+        }
+        // when using bundle, avoid adding candidates to the wrong
+        // ice transport. And avoid adding candidates added in the SDP.
+        if (sdpMLineIndex === 0 || (sdpMLineIndex > 0 &&
+            transceiver.iceTransport !== this.transceivers[0].iceTransport)) {
+          if (!maybeAddCandidate(transceiver.iceTransport, cand)) {
+            err = new Error('Can not add ICE candidate');
+            err.name = 'OperationError';
+          }
+        }
+
+        if (!err) {
+          // update the remoteDescription.
+          var candidateString = candidate.candidate.trim();
+          if (candidateString.indexOf('a=') === 0) {
+            candidateString = candidateString.substr(2);
+          }
+          sections = SDPUtils.splitSections(this.remoteDescription.sdp);
+          sections[sdpMLineIndex + 1] += 'a=' +
+              (cand.type ? candidateString : 'end-of-candidates')
+              + '\r\n';
+          this.remoteDescription.sdp = sections.join('');
+        }
+      } else {
+        err = new Error('Can not add ICE candidate');
+        err.name = 'OperationError';
+      }
+    }
+    var args = arguments;
+    return new Promise(function(resolve, reject) {
+      if (err) {
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [err]);
+        }
+        reject(err);
+      } else {
+        if (args.length > 1 && typeof args[1] === 'function') {
+          args[1].apply(null);
+        }
+        resolve();
+      }
+    });
+  };
+
+  RTCPeerConnection.prototype.getStats = function() {
+    var promises = [];
+    this.transceivers.forEach(function(transceiver) {
+      ['rtpSender', 'rtpReceiver', 'iceGatherer', 'iceTransport',
+          'dtlsTransport'].forEach(function(method) {
+            if (transceiver[method]) {
+              promises.push(transceiver[method].getStats());
+            }
+          });
+    });
+    var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
+        arguments[1];
+    var fixStatsType = function(stat) {
+      return {
+        inboundrtp: 'inbound-rtp',
+        outboundrtp: 'outbound-rtp',
+        candidatepair: 'candidate-pair',
+        localcandidate: 'local-candidate',
+        remotecandidate: 'remote-candidate'
+      }[stat.type] || stat.type;
+    };
+    return new Promise(function(resolve) {
+      // shim getStats with maplike support
+      var results = new Map();
+      Promise.all(promises).then(function(res) {
+        res.forEach(function(result) {
+          Object.keys(result).forEach(function(id) {
+            result[id].type = fixStatsType(result[id]);
+            results.set(id, result[id]);
+          });
+        });
+        if (cb) {
+          cb.apply(null, results);
+        }
+        resolve(results);
+      });
+    });
+  };
+  return RTCPeerConnection;
+};
+
+},{"sdp":2}],2:[function(require,module,exports){
+ /* eslint-env node */
+'use strict';
+
+// SDP helpers.
+var SDPUtils = {};
+
+// Generate an alphanumeric identifier for cname or mids.
+// TODO: use UUIDs instead? https://gist.github.com/jed/982883
+SDPUtils.generateIdentifier = function() {
+  return Math.random().toString(36).substr(2, 10);
+};
+
+// The RTCP CNAME used by all peerconnections from the same JS.
+SDPUtils.localCName = SDPUtils.generateIdentifier();
+
+// Splits SDP into lines, dealing with both CRLF and LF.
+SDPUtils.splitLines = function(blob) {
+  return blob.trim().split('\n').map(function(line) {
+    return line.trim();
+  });
+};
+// Splits SDP into sessionpart and mediasections. Ensures CRLF.
+SDPUtils.splitSections = function(blob) {
+  var parts = blob.split('\nm=');
+  return parts.map(function(part, index) {
+    return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
+  });
+};
+
+// Returns lines that start with a certain prefix.
+SDPUtils.matchPrefix = function(blob, prefix) {
+  return SDPUtils.splitLines(blob).filter(function(line) {
+    return line.indexOf(prefix) === 0;
+  });
+};
+
+// Parses an ICE candidate line. Sample input:
+// candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8
+// rport 55996"
+SDPUtils.parseCandidate = function(line) {
+  var parts;
+  // Parse both variants.
+  if (line.indexOf('a=candidate:') === 0) {
+    parts = line.substring(12).split(' ');
+  } else {
+    parts = line.substring(10).split(' ');
+  }
+
+  var candidate = {
+    foundation: parts[0],
+    component: parseInt(parts[1], 10),
+    protocol: parts[2].toLowerCase(),
+    priority: parseInt(parts[3], 10),
+    ip: parts[4],
+    port: parseInt(parts[5], 10),
+    // skip parts[6] == 'typ'
+    type: parts[7]
+  };
+
+  for (var i = 8; i < parts.length; i += 2) {
+    switch (parts[i]) {
+      case 'raddr':
+        candidate.relatedAddress = parts[i + 1];
+        break;
+      case 'rport':
+        candidate.relatedPort = parseInt(parts[i + 1], 10);
+        break;
+      case 'tcptype':
+        candidate.tcpType = parts[i + 1];
+        break;
+      case 'ufrag':
+        candidate.ufrag = parts[i + 1]; // for backward compability.
+        candidate.usernameFragment = parts[i + 1];
+        break;
+      default: // extension handling, in particular ufrag
+        candidate[parts[i]] = parts[i + 1];
+        break;
+    }
+  }
+  return candidate;
+};
+
+// Translates a candidate object into SDP candidate attribute.
+SDPUtils.writeCandidate = function(candidate) {
+  var sdp = [];
+  sdp.push(candidate.foundation);
+  sdp.push(candidate.component);
+  sdp.push(candidate.protocol.toUpperCase());
+  sdp.push(candidate.priority);
+  sdp.push(candidate.ip);
+  sdp.push(candidate.port);
+
+  var type = candidate.type;
+  sdp.push('typ');
+  sdp.push(type);
+  if (type !== 'host' && candidate.relatedAddress &&
+      candidate.relatedPort) {
+    sdp.push('raddr');
+    sdp.push(candidate.relatedAddress); // was: relAddr
+    sdp.push('rport');
+    sdp.push(candidate.relatedPort); // was: relPort
+  }
+  if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
+    sdp.push('tcptype');
+    sdp.push(candidate.tcpType);
+  }
+  if (candidate.ufrag) {
+    sdp.push('ufrag');
+    sdp.push(candidate.ufrag);
+  }
+  return 'candidate:' + sdp.join(' ');
+};
+
+// Parses an ice-options line, returns an array of option tags.
+// a=ice-options:foo bar
+SDPUtils.parseIceOptions = function(line) {
+  return line.substr(14).split(' ');
+}
+
+// Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
+// a=rtpmap:111 opus/48000/2
+SDPUtils.parseRtpMap = function(line) {
+  var parts = line.substr(9).split(' ');
+  var parsed = {
+    payloadType: parseInt(parts.shift(), 10) // was: id
+  };
+
+  parts = parts[0].split('/');
+
+  parsed.name = parts[0];
+  parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
+  // was: channels
+  parsed.numChannels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
+  return parsed;
+};
+
+// Generate an a=rtpmap line from RTCRtpCodecCapability or
+// RTCRtpCodecParameters.
+SDPUtils.writeRtpMap = function(codec) {
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
+      (codec.numChannels !== 1 ? '/' + codec.numChannels : '') + '\r\n';
+};
+
+// Parses an a=extmap line (headerextension from RFC 5285). Sample input:
+// a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
+// a=extmap:2/sendonly urn:ietf:params:rtp-hdrext:toffset
+SDPUtils.parseExtmap = function(line) {
+  var parts = line.substr(9).split(' ');
+  return {
+    id: parseInt(parts[0], 10),
+    direction: parts[0].indexOf('/') > 0 ? parts[0].split('/')[1] : 'sendrecv',
+    uri: parts[1]
+  };
+};
+
+// Generates a=extmap line from RTCRtpHeaderExtensionParameters or
+// RTCRtpHeaderExtension.
+SDPUtils.writeExtmap = function(headerExtension) {
+  return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
+      (headerExtension.direction && headerExtension.direction !== 'sendrecv'
+          ? '/' + headerExtension.direction
+          : '') +
+      ' ' + headerExtension.uri + '\r\n';
+};
+
+// Parses an ftmp line, returns dictionary. Sample input:
+// a=fmtp:96 vbr=on;cng=on
+// Also deals with vbr=on; cng=on
+SDPUtils.parseFmtp = function(line) {
+  var parsed = {};
+  var kv;
+  var parts = line.substr(line.indexOf(' ') + 1).split(';');
+  for (var j = 0; j < parts.length; j++) {
+    kv = parts[j].trim().split('=');
+    parsed[kv[0].trim()] = kv[1];
+  }
+  return parsed;
+};
+
+// Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeFmtp = function(codec) {
+  var line = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.parameters && Object.keys(codec.parameters).length) {
+    var params = [];
+    Object.keys(codec.parameters).forEach(function(param) {
+      params.push(param + '=' + codec.parameters[param]);
+    });
+    line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
+  }
+  return line;
+};
+
+// Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
+// a=rtcp-fb:98 nack rpsi
+SDPUtils.parseRtcpFb = function(line) {
+  var parts = line.substr(line.indexOf(' ') + 1).split(' ');
+  return {
+    type: parts.shift(),
+    parameter: parts.join(' ')
+  };
+};
+// Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeRtcpFb = function(codec) {
+  var lines = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
+    // FIXME: special handling for trr-int?
+    codec.rtcpFeedback.forEach(function(fb) {
+      lines += 'a=rtcp-fb:' + pt + ' ' + fb.type +
+      (fb.parameter && fb.parameter.length ? ' ' + fb.parameter : '') +
+          '\r\n';
+    });
+  }
+  return lines;
+};
+
+// Parses an RFC 5576 ssrc media attribute. Sample input:
+// a=ssrc:3735928559 cname:something
+SDPUtils.parseSsrcMedia = function(line) {
+  var sp = line.indexOf(' ');
+  var parts = {
+    ssrc: parseInt(line.substr(7, sp - 7), 10)
+  };
+  var colon = line.indexOf(':', sp);
+  if (colon > -1) {
+    parts.attribute = line.substr(sp + 1, colon - sp - 1);
+    parts.value = line.substr(colon + 1);
+  } else {
+    parts.attribute = line.substr(sp + 1);
+  }
+  return parts;
+};
+
+// Extracts the MID (RFC 5888) from a media section.
+// returns the MID or undefined if no mid line was found.
+SDPUtils.getMid = function(mediaSection) {
+  var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0];
+  if (mid) {
+    return mid.substr(6);
+  }
+}
+
+SDPUtils.parseFingerprint = function(line) {
+  var parts = line.substr(14).split(' ');
+  return {
+    algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
+    value: parts[1]
+  };
+};
+
+// Extracts DTLS parameters from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the fingerprint line as input. See also getIceParameters.
+SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.matchPrefix(mediaSection + sessionpart,
+      'a=fingerprint:');
+  // Note: a=setup line is ignored since we use the 'auto' role.
+  // Note2: 'algorithm' is not case sensitive except in Edge.
+  return {
+    role: 'auto',
+    fingerprints: lines.map(SDPUtils.parseFingerprint)
+  };
+};
+
+// Serializes DTLS parameters to SDP.
+SDPUtils.writeDtlsParameters = function(params, setupType) {
+  var sdp = 'a=setup:' + setupType + '\r\n';
+  params.fingerprints.forEach(function(fp) {
+    sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
+  });
+  return sdp;
+};
+// Parses ICE information from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the ice-ufrag and ice-pwd lines as input.
+SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  // Search in session part, too.
+  lines = lines.concat(SDPUtils.splitLines(sessionpart));
+  var iceParameters = {
+    usernameFragment: lines.filter(function(line) {
+      return line.indexOf('a=ice-ufrag:') === 0;
+    })[0].substr(12),
+    password: lines.filter(function(line) {
+      return line.indexOf('a=ice-pwd:') === 0;
+    })[0].substr(10)
+  };
+  return iceParameters;
+};
+
+// Serializes ICE parameters to SDP.
+SDPUtils.writeIceParameters = function(params) {
+  return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
+      'a=ice-pwd:' + params.password + '\r\n';
+};
+
+// Parses the SDP media section and returns RTCRtpParameters.
+SDPUtils.parseRtpParameters = function(mediaSection) {
+  var description = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: [],
+    rtcp: []
+  };
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
+    var pt = mline[i];
+    var rtpmapline = SDPUtils.matchPrefix(
+        mediaSection, 'a=rtpmap:' + pt + ' ')[0];
+    if (rtpmapline) {
+      var codec = SDPUtils.parseRtpMap(rtpmapline);
+      var fmtps = SDPUtils.matchPrefix(
+          mediaSection, 'a=fmtp:' + pt + ' ');
+      // Only the first a=fmtp:<pt> is considered.
+      codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
+      codec.rtcpFeedback = SDPUtils.matchPrefix(
+          mediaSection, 'a=rtcp-fb:' + pt + ' ')
+        .map(SDPUtils.parseRtcpFb);
+      description.codecs.push(codec);
+      // parse FEC mechanisms from rtpmap lines.
+      switch (codec.name.toUpperCase()) {
+        case 'RED':
+        case 'ULPFEC':
+          description.fecMechanisms.push(codec.name.toUpperCase());
+          break;
+        default: // only RED and ULPFEC are recognized as FEC mechanisms.
+          break;
+      }
+    }
+  }
+  SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
+    description.headerExtensions.push(SDPUtils.parseExtmap(line));
+  });
+  // FIXME: parse rtcp.
+  return description;
+};
+
+// Generates parts of the SDP media section describing the capabilities /
+// parameters.
+SDPUtils.writeRtpDescription = function(kind, caps) {
+  var sdp = '';
+
+  // Build the mline.
+  sdp += 'm=' + kind + ' ';
+  sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
+  sdp += ' UDP/TLS/RTP/SAVPF ';
+  sdp += caps.codecs.map(function(codec) {
+    if (codec.preferredPayloadType !== undefined) {
+      return codec.preferredPayloadType;
+    }
+    return codec.payloadType;
+  }).join(' ') + '\r\n';
+
+  sdp += 'c=IN IP4 0.0.0.0\r\n';
+  sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';
+
+  // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
+  caps.codecs.forEach(function(codec) {
+    sdp += SDPUtils.writeRtpMap(codec);
+    sdp += SDPUtils.writeFmtp(codec);
+    sdp += SDPUtils.writeRtcpFb(codec);
+  });
+  var maxptime = 0;
+  caps.codecs.forEach(function(codec) {
+    if (codec.maxptime > maxptime) {
+      maxptime = codec.maxptime;
+    }
+  });
+  if (maxptime > 0) {
+    sdp += 'a=maxptime:' + maxptime + '\r\n';
+  }
+  sdp += 'a=rtcp-mux\r\n';
+
+  caps.headerExtensions.forEach(function(extension) {
+    sdp += SDPUtils.writeExtmap(extension);
+  });
+  // FIXME: write fecMechanisms.
+  return sdp;
+};
+
+// Parses the SDP media section and returns an array of
+// RTCRtpEncodingParameters.
+SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
+  var encodingParameters = [];
+  var description = SDPUtils.parseRtpParameters(mediaSection);
+  var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
+  var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;
+
+  // filter a=ssrc:... cname:, ignore PlanB-msid
+  var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'cname';
+  });
+  var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
+  var secondarySsrc;
+
+  var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
+  .map(function(line) {
+    var parts = line.split(' ');
+    parts.shift();
+    return parts.map(function(part) {
+      return parseInt(part, 10);
+    });
+  });
+  if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
+    secondarySsrc = flows[0][1];
+  }
+
+  description.codecs.forEach(function(codec) {
+    if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
+      var encParam = {
+        ssrc: primarySsrc,
+        codecPayloadType: parseInt(codec.parameters.apt, 10),
+        rtx: {
+          ssrc: secondarySsrc
+        }
+      };
+      encodingParameters.push(encParam);
+      if (hasRed) {
+        encParam = JSON.parse(JSON.stringify(encParam));
+        encParam.fec = {
+          ssrc: secondarySsrc,
+          mechanism: hasUlpfec ? 'red+ulpfec' : 'red'
+        };
+        encodingParameters.push(encParam);
+      }
+    }
+  });
+  if (encodingParameters.length === 0 && primarySsrc) {
+    encodingParameters.push({
+      ssrc: primarySsrc
+    });
+  }
+
+  // we support both b=AS and b=TIAS but interpret AS as TIAS.
+  var bandwidth = SDPUtils.matchPrefix(mediaSection, 'b=');
+  if (bandwidth.length) {
+    if (bandwidth[0].indexOf('b=TIAS:') === 0) {
+      bandwidth = parseInt(bandwidth[0].substr(7), 10);
+    } else if (bandwidth[0].indexOf('b=AS:') === 0) {
+      // use formula from JSEP to convert b=AS to TIAS value.
+      bandwidth = parseInt(bandwidth[0].substr(5), 10) * 1000 * 0.95
+          - (50 * 40 * 8);
+    } else {
+      bandwidth = undefined;
+    }
+    encodingParameters.forEach(function(params) {
+      params.maxBitrate = bandwidth;
+    });
+  }
+  return encodingParameters;
+};
+
+// parses http://draft.ortc.org/#rtcrtcpparameters*
+SDPUtils.parseRtcpParameters = function(mediaSection) {
+  var rtcpParameters = {};
+
+  var cname;
+  // Gets the first SSRC. Note that with RTX there might be multiple
+  // SSRCs.
+  var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+      .map(function(line) {
+        return SDPUtils.parseSsrcMedia(line);
+      })
+      .filter(function(obj) {
+        return obj.attribute === 'cname';
+      })[0];
+  if (remoteSsrc) {
+    rtcpParameters.cname = remoteSsrc.value;
+    rtcpParameters.ssrc = remoteSsrc.ssrc;
+  }
+
+  // Edge uses the compound attribute instead of reducedSize
+  // compound is !reducedSize
+  var rsize = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-rsize');
+  rtcpParameters.reducedSize = rsize.length > 0;
+  rtcpParameters.compound = rsize.length === 0;
+
+  // parses the rtcp-mux attrіbute.
+  // Note that Edge does not support unmuxed RTCP.
+  var mux = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-mux');
+  rtcpParameters.mux = mux.length > 0;
+
+  return rtcpParameters;
+};
+
+// parses either a=msid: or a=ssrc:... msid lines and returns
+// the id of the MediaStream and MediaStreamTrack.
+SDPUtils.parseMsid = function(mediaSection) {
+  var parts;
+  var spec = SDPUtils.matchPrefix(mediaSection, 'a=msid:');
+  if (spec.length === 1) {
+    parts = spec[0].substr(7).split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+  var planB = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'msid';
+  });
+  if (planB.length > 0) {
+    parts = planB[0].value.split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+};
+
+// Generate a session ID for SDP.
+// https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-20#section-5.2.1
+// recommends using a cryptographically random +ve 64-bit value
+// but right now this should be acceptable and within the right range
+SDPUtils.generateSessionId = function() {
+  return Math.random().toString().substr(2, 21);
+};
+
+// Write boilder plate for start of SDP
+// sessId argument is optional - if not supplied it will
+// be generated randomly
+// sessVersion is optional and defaults to 2
+SDPUtils.writeSessionBoilerplate = function(sessId, sessVer) {
+  var sessionId;
+  var version = sessVer !== undefined ? sessVer : 2;
+  if (sessId) {
+    sessionId = sessId;
+  } else {
+    sessionId = SDPUtils.generateSessionId();
+  }
+  // FIXME: sess-id should be an NTP timestamp.
+  return 'v=0\r\n' +
+      'o=thisisadapterortc ' + sessionId + ' ' + version + ' IN IP4 127.0.0.1\r\n' +
+      's=-\r\n' +
+      't=0 0\r\n';
+};
+
+SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+};
+
+// Gets the direction from the mediaSection or the sessionpart.
+SDPUtils.getDirection = function(mediaSection, sessionpart) {
+  // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
+  var lines = SDPUtils.splitLines(mediaSection);
+  for (var i = 0; i < lines.length; i++) {
+    switch (lines[i]) {
+      case 'a=sendrecv':
+      case 'a=sendonly':
+      case 'a=recvonly':
+      case 'a=inactive':
+        return lines[i].substr(2);
+      default:
+        // FIXME: What should happen here?
+    }
+  }
+  if (sessionpart) {
+    return SDPUtils.getDirection(sessionpart);
+  }
+  return 'sendrecv';
+};
+
+SDPUtils.getKind = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return mline[0].substr(2);
+};
+
+SDPUtils.isRejected = function(mediaSection) {
+  return mediaSection.split(' ', 2)[1] === '0';
+};
+
+SDPUtils.parseMLine = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return {
+    kind: mline[0].substr(2),
+    port: parseInt(mline[1], 10),
+    protocol: mline[2],
+    fmt: mline.slice(3).join(' ')
+  };
+};
+
+// Expose public methods.
+if (typeof module === 'object') {
+  module.exports = SDPUtils;
+}
+
+},{}],3:[function(require,module,exports){
+(function (global){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var adapterFactory = require('./adapter_factory.js');
+module.exports = adapterFactory({window: global.window});
+
+}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
+},{"./adapter_factory.js":4}],4:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var utils = require('./utils');
+// Shimming starts here.
+module.exports = function(dependencies, opts) {
+  var window = dependencies && dependencies.window;
+
+  var options = {
+    shimChrome: true,
+    shimFirefox: true,
+    shimEdge: true,
+    shimSafari: true,
+  };
+
+  for (var key in opts) {
+    if (hasOwnProperty.call(opts, key)) {
+      options[key] = opts[key];
+    }
+  }
+
+  // Utils.
+  var logging = utils.log;
+  var browserDetails = utils.detectBrowser(window);
+
+  // Export to the adapter global object visible in the browser.
+  var adapter = {
+    browserDetails: browserDetails,
+    extractVersion: utils.extractVersion,
+    disableLog: utils.disableLog,
+    disableWarnings: utils.disableWarnings
+  };
+
+  // Uncomment the line below if you want logging to occur, including logging
+  // for the switch statement below. Can also be turned on in the browser via
+  // adapter.disableLog(false), but then logging from the switch statement below
+  // will not appear.
+  // require('./utils').disableLog(false);
+
+  // Browser shims.
+  var chromeShim = require('./chrome/chrome_shim') || null;
+  var edgeShim = require('./edge/edge_shim') || null;
+  var firefoxShim = require('./firefox/firefox_shim') || null;
+  var safariShim = require('./safari/safari_shim') || null;
+  var commonShim = require('./common_shim') || null;
+
+  // Shim browser if found.
+  switch (browserDetails.browser) {
+    case 'chrome':
+      if (!chromeShim || !chromeShim.shimPeerConnection ||
+          !options.shimChrome) {
+        logging('Chrome shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      chromeShim.shimGetUserMedia(window);
+      chromeShim.shimMediaStream(window);
+      chromeShim.shimSourceObject(window);
+      chromeShim.shimPeerConnection(window);
+      chromeShim.shimOnTrack(window);
+      chromeShim.shimAddTrackRemoveTrack(window);
+      chromeShim.shimGetSendersWithDtmf(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'firefox':
+      if (!firefoxShim || !firefoxShim.shimPeerConnection ||
+          !options.shimFirefox) {
+        logging('Firefox shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming firefox.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = firefoxShim;
+      commonShim.shimCreateObjectURL(window);
+
+      firefoxShim.shimGetUserMedia(window);
+      firefoxShim.shimSourceObject(window);
+      firefoxShim.shimPeerConnection(window);
+      firefoxShim.shimOnTrack(window);
+      firefoxShim.shimRemoveStream(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'edge':
+      if (!edgeShim || !edgeShim.shimPeerConnection || !options.shimEdge) {
+        logging('MS edge shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming edge.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = edgeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      edgeShim.shimGetUserMedia(window);
+      edgeShim.shimPeerConnection(window);
+      edgeShim.shimReplaceTrack(window);
+
+      // the edge shim implements the full RTCIceCandidate object.
+      break;
+    case 'safari':
+      if (!safariShim || !options.shimSafari) {
+        logging('Safari shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming safari.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = safariShim;
+      commonShim.shimCreateObjectURL(window);
+
+      safariShim.shimRTCIceServerUrls(window);
+      safariShim.shimCallbacksAPI(window);
+      safariShim.shimLocalStreamsAPI(window);
+      safariShim.shimRemoteStreamsAPI(window);
+      safariShim.shimTrackEventTransceiver(window);
+      safariShim.shimGetUserMedia(window);
+      safariShim.shimCreateOfferLegacy(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+
+  return adapter;
+};
+
+},{"./chrome/chrome_shim":5,"./common_shim":7,"./edge/edge_shim":8,"./firefox/firefox_shim":10,"./safari/safari_shim":12,"./utils":13}],5:[function(require,module,exports){
+
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+var chromeShim = {
+  shimMediaStream: function(window) {
+    window.MediaStream = window.MediaStream || window.webkitMediaStream;
+  },
+
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+          }
+          this.addEventListener('track', this._ontrack = f);
+        }
+      });
+      var origSetRemoteDescription =
+          window.RTCPeerConnection.prototype.setRemoteDescription;
+      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
+        var pc = this;
+        if (!pc._ontrackpoly) {
+          pc._ontrackpoly = function(e) {
+            // onaddstream does not fire when a track is added to an existing
+            // stream. But stream.onaddtrack is implemented so we use that.
+            e.stream.addEventListener('addtrack', function(te) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === te.track.id;
+                });
+              } else {
+                receiver = {track: te.track};
+              }
+
+              var event = new Event('track');
+              event.track = te.track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+            e.stream.getTracks().forEach(function(track) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === track.id;
+                });
+              } else {
+                receiver = {track: track};
+              }
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+          };
+          pc.addEventListener('addstream', pc._ontrackpoly);
+        }
+        return origSetRemoteDescription.apply(pc, arguments);
+      };
+    }
+  },
+
+  shimGetSendersWithDtmf: function(window) {
+    // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        !('getSenders' in window.RTCPeerConnection.prototype) &&
+        'createDTMFSender' in window.RTCPeerConnection.prototype) {
+      var shimSenderWithDtmf = function(pc, track) {
+        return {
+          track: track,
+          get dtmf() {
+            if (this._dtmf === undefined) {
+              if (track.kind === 'audio') {
+                this._dtmf = pc.createDTMFSender(track);
+              } else {
+                this._dtmf = null;
+              }
+            }
+            return this._dtmf;
+          },
+          _pc: pc
+        };
+      };
+
+      // augment addTrack when getSenders is not available.
+      if (!window.RTCPeerConnection.prototype.getSenders) {
+        window.RTCPeerConnection.prototype.getSenders = function() {
+          this._senders = this._senders || [];
+          return this._senders.slice(); // return a copy of the internal state.
+        };
+        var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+        window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+          var pc = this;
+          var sender = origAddTrack.apply(pc, arguments);
+          if (!sender) {
+            sender = shimSenderWithDtmf(pc, track);
+            pc._senders.push(sender);
+          }
+          return sender;
+        };
+
+        var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+        window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+          var pc = this;
+          origRemoveTrack.apply(pc, arguments);
+          var idx = pc._senders.indexOf(sender);
+          if (idx !== -1) {
+            pc._senders.splice(idx, 1);
+          }
+        };
+      }
+      var origAddStream = window.RTCPeerConnection.prototype.addStream;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origAddStream.apply(pc, [stream]);
+        stream.getTracks().forEach(function(track) {
+          pc._senders.push(shimSenderWithDtmf(pc, track));
+        });
+      };
+
+      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origRemoveStream.apply(pc, [stream]);
+
+        stream.getTracks().forEach(function(track) {
+          var sender = pc._senders.find(function(s) {
+            return s.track === track;
+          });
+          if (sender) {
+            pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
+          }
+        });
+      };
+    } else if (typeof window === 'object' && window.RTCPeerConnection &&
+               'getSenders' in window.RTCPeerConnection.prototype &&
+               'createDTMFSender' in window.RTCPeerConnection.prototype &&
+               window.RTCRtpSender &&
+               !('dtmf' in window.RTCRtpSender.prototype)) {
+      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+      window.RTCPeerConnection.prototype.getSenders = function() {
+        var pc = this;
+        var senders = origGetSenders.apply(pc, []);
+        senders.forEach(function(sender) {
+          sender._pc = pc;
+        });
+        return senders;
+      };
+
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = this._pc.createDTMFSender(this.track);
+            } else {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    var URL = window && window.URL;
+
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this._srcObject;
+          },
+          set: function(stream) {
+            var self = this;
+            // Use _srcObject as a private property for this shim
+            this._srcObject = stream;
+            if (this.src) {
+              URL.revokeObjectURL(this.src);
+            }
+
+            if (!stream) {
+              this.src = '';
+              return undefined;
+            }
+            this.src = URL.createObjectURL(stream);
+            // We need to recreate the blob url when a track is added or
+            // removed. Doing it manually since we want to avoid a recursion.
+            stream.addEventListener('addtrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+            stream.addEventListener('removetrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+          }
+        });
+      }
+    }
+  },
+
+  shimAddTrackRemoveTrack: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+    // shim addTrack and removeTrack.
+    if (window.RTCPeerConnection.prototype.addTrack &&
+        browserDetails.version >= 64) {
+      return;
+    }
+
+    // also shim pc.getLocalStreams when addTrack is shimmed
+    // to return the original streams.
+    var origGetLocalStreams = window.RTCPeerConnection.prototype
+        .getLocalStreams;
+    window.RTCPeerConnection.prototype.getLocalStreams = function() {
+      var self = this;
+      var nativeStreams = origGetLocalStreams.apply(this);
+      self._reverseStreams = self._reverseStreams || {};
+      return nativeStreams.map(function(stream) {
+        return self._reverseStreams[stream.id];
+      });
+    };
+
+    var origAddStream = window.RTCPeerConnection.prototype.addStream;
+    window.RTCPeerConnection.prototype.addStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      stream.getTracks().forEach(function(track) {
+        var alreadyExists = pc.getSenders().find(function(s) {
+          return s.track === track;
+        });
+        if (alreadyExists) {
+          throw new DOMException('Track already exists.',
+              'InvalidAccessError');
+        }
+      });
+      // Add identity mapping for consistency with addTrack.
+      // Unless this is being used with a stream from addTrack.
+      if (!pc._reverseStreams[stream.id]) {
+        var newStream = new window.MediaStream(stream.getTracks());
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        stream = newStream;
+      }
+      origAddStream.apply(pc, [stream]);
+    };
+
+    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
+      delete pc._reverseStreams[(pc._streams[stream.id] ?
+          pc._streams[stream.id].id : stream.id)];
+      delete pc._streams[stream.id];
+    };
+
+    window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      var streams = [].slice.call(arguments, 1);
+      if (streams.length !== 1 ||
+          !streams[0].getTracks().find(function(t) {
+            return t === track;
+          })) {
+        // this is not fully correct but all we can manage without
+        // [[associated MediaStreams]] internal slot.
+        throw new DOMException(
+          'The adapter.js addTrack polyfill only supports a single ' +
+          ' stream which is associated with the specified track.',
+          'NotSupportedError');
+      }
+
+      var alreadyExists = pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+            'InvalidAccessError');
+      }
+
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+      var oldStream = pc._streams[stream.id];
+      if (oldStream) {
+        // this is using odd Chrome behaviour, use with caution:
+        // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
+        // Note: we rely on the high-level addTrack/dtmf shim to
+        // create the sender with a dtmf sender.
+        oldStream.addTrack(track);
+
+        // Trigger ONN async.
+        Promise.resolve().then(function() {
+          pc.dispatchEvent(new Event('negotiationneeded'));
+        });
+      } else {
+        var newStream = new window.MediaStream([track]);
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        pc.addStream(newStream);
+      }
+      return pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+    };
+
+    // replace the internal stream id with the external one and
+    // vice versa.
+    function replaceInternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
+            externalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    function replaceExternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
+            internalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    ['createOffer', 'createAnswer'].forEach(function(method) {
+      var nativeMethod = window.RTCPeerConnection.prototype[method];
+      window.RTCPeerConnection.prototype[method] = function() {
+        var pc = this;
+        var args = arguments;
+        var isLegacyCall = arguments.length &&
+            typeof arguments[0] === 'function';
+        if (isLegacyCall) {
+          return nativeMethod.apply(pc, [
+            function(description) {
+              var desc = replaceInternalStreamId(pc, description);
+              args[0].apply(null, [desc]);
+            },
+            function(err) {
+              if (args[1]) {
+                args[1].apply(null, err);
+              }
+            }, arguments[2]
+          ]);
+        }
+        return nativeMethod.apply(pc, arguments)
+        .then(function(description) {
+          return replaceInternalStreamId(pc, description);
+        });
+      };
+    });
+
+    var origSetLocalDescription =
+        window.RTCPeerConnection.prototype.setLocalDescription;
+    window.RTCPeerConnection.prototype.setLocalDescription = function() {
+      var pc = this;
+      if (!arguments.length || !arguments[0].type) {
+        return origSetLocalDescription.apply(pc, arguments);
+      }
+      arguments[0] = replaceExternalStreamId(pc, arguments[0]);
+      return origSetLocalDescription.apply(pc, arguments);
+    };
+
+    // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
+
+    var origLocalDescription = Object.getOwnPropertyDescriptor(
+        window.RTCPeerConnection.prototype, 'localDescription');
+    Object.defineProperty(window.RTCPeerConnection.prototype,
+        'localDescription', {
+          get: function() {
+            var pc = this;
+            var description = origLocalDescription.get.apply(this);
+            if (description.type === '') {
+              return description;
+            }
+            return replaceInternalStreamId(pc, description);
+          }
+        });
+
+    window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      // We can not yet check for sender instanceof RTCRtpSender
+      // since we shim RTPSender. So we check if sender._pc is set.
+      if (!sender._pc) {
+        throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
+            'does not implement interface RTCRtpSender.', 'TypeError');
+      }
+      var isLocal = sender._pc === pc;
+      if (!isLocal) {
+        throw new DOMException('Sender was not created by this connection.',
+            'InvalidAccessError');
+      }
+
+      // Search for the native stream the senders track belongs to.
+      pc._streams = pc._streams || {};
+      var stream;
+      Object.keys(pc._streams).forEach(function(streamid) {
+        var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
+          return sender.track === track;
+        });
+        if (hasTrack) {
+          stream = pc._streams[streamid];
+        }
+      });
+
+      if (stream) {
+        if (stream.getTracks().length === 1) {
+          // if this is the last track of the stream, remove the stream. This
+          // takes care of any shimmed _senders.
+          pc.removeStream(pc._reverseStreams[stream.id]);
+        } else {
+          // relying on the same odd chrome behaviour as above.
+          stream.removeTrack(sender.track);
+        }
+        pc.dispatchEvent(new Event('negotiationneeded'));
+      }
+    };
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        // Translate iceTransportPolicy to iceTransports,
+        // see https://code.google.com/p/webrtc/issues/detail?id=4869
+        // this was fixed in M56 along with unprefixing RTCPeerConnection.
+        logging('PeerConnection');
+        if (pcConfig && pcConfig.iceTransportPolicy) {
+          pcConfig.iceTransports = pcConfig.iceTransportPolicy;
+        }
+
+        return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.webkitRTCPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      if (window.webkitRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.webkitRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+    } else {
+      // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+      var OrigPeerConnection = window.RTCPeerConnection;
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (pcConfig && pcConfig.iceServers) {
+          var newIceServers = [];
+          for (var i = 0; i < pcConfig.iceServers.length; i++) {
+            var server = pcConfig.iceServers[i];
+            if (!server.hasOwnProperty('urls') &&
+                server.hasOwnProperty('url')) {
+              utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+              server = JSON.parse(JSON.stringify(server));
+              server.urls = server.url;
+              newIceServers.push(server);
+            } else {
+              newIceServers.push(pcConfig.iceServers[i]);
+            }
+          }
+          pcConfig.iceServers = newIceServers;
+        }
+        return new OrigPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+
+    var origGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(selector,
+        successCallback, errorCallback) {
+      var self = this;
+      var args = arguments;
+
+      // If selector is a function then we are in the old style stats so just
+      // pass back the original getStats format to avoid breaking old users.
+      if (arguments.length > 0 && typeof selector === 'function') {
+        return origGetStats.apply(this, arguments);
+      }
+
+      // When spec-style getStats is supported, return those when called with
+      // either no arguments or the selector argument is null.
+      if (origGetStats.length === 0 && (arguments.length === 0 ||
+          typeof arguments[0] !== 'function')) {
+        return origGetStats.apply(this, []);
+      }
+
+      var fixChromeStats_ = function(response) {
+        var standardReport = {};
+        var reports = response.result();
+        reports.forEach(function(report) {
+          var standardStats = {
+            id: report.id,
+            timestamp: report.timestamp,
+            type: {
+              localcandidate: 'local-candidate',
+              remotecandidate: 'remote-candidate'
+            }[report.type] || report.type
+          };
+          report.names().forEach(function(name) {
+            standardStats[name] = report.stat(name);
+          });
+          standardReport[standardStats.id] = standardStats;
+        });
+
+        return standardReport;
+      };
+
+      // shim getStats with maplike support
+      var makeMapStats = function(stats) {
+        return new Map(Object.keys(stats).map(function(key) {
+          return [key, stats[key]];
+        }));
+      };
+
+      if (arguments.length >= 2) {
+        var successCallbackWrapper_ = function(response) {
+          args[1](makeMapStats(fixChromeStats_(response)));
+        };
+
+        return origGetStats.apply(this, [successCallbackWrapper_,
+          arguments[0]]);
+      }
+
+      // promise-support
+      return new Promise(function(resolve, reject) {
+        origGetStats.apply(self, [
+          function(response) {
+            resolve(makeMapStats(fixChromeStats_(response)));
+          }, reject]);
+      }).then(successCallback, errorCallback);
+    };
+
+    // add promise support -- natively available in Chrome 51
+    if (browserDetails.version < 51) {
+      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+          .forEach(function(method) {
+            var nativeMethod = window.RTCPeerConnection.prototype[method];
+            window.RTCPeerConnection.prototype[method] = function() {
+              var args = arguments;
+              var self = this;
+              var promise = new Promise(function(resolve, reject) {
+                nativeMethod.apply(self, [args[0], resolve, reject]);
+              });
+              if (args.length < 2) {
+                return promise;
+              }
+              return promise.then(function() {
+                args[1].apply(null, []);
+              },
+              function(err) {
+                if (args.length >= 3) {
+                  args[2].apply(null, [err]);
+                }
+              });
+            };
+          });
+    }
+
+    // promise support for createOffer and createAnswer. Available (without
+    // bugs) since M52: crbug/619289
+    if (browserDetails.version < 52) {
+      ['createOffer', 'createAnswer'].forEach(function(method) {
+        var nativeMethod = window.RTCPeerConnection.prototype[method];
+        window.RTCPeerConnection.prototype[method] = function() {
+          var self = this;
+          if (arguments.length < 1 || (arguments.length === 1 &&
+              typeof arguments[0] === 'object')) {
+            var opts = arguments.length === 1 ? arguments[0] : undefined;
+            return new Promise(function(resolve, reject) {
+              nativeMethod.apply(self, [resolve, reject, opts]);
+            });
+          }
+          return nativeMethod.apply(this, arguments);
+        };
+      });
+    }
+
+    // shim implicit creation of RTCSessionDescription/RTCIceCandidate
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+  }
+};
+
+
+// Expose public methods.
+module.exports = {
+  shimMediaStream: chromeShim.shimMediaStream,
+  shimOnTrack: chromeShim.shimOnTrack,
+  shimAddTrackRemoveTrack: chromeShim.shimAddTrackRemoveTrack,
+  shimGetSendersWithDtmf: chromeShim.shimGetSendersWithDtmf,
+  shimSourceObject: chromeShim.shimSourceObject,
+  shimPeerConnection: chromeShim.shimPeerConnection,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils.js":13,"./getusermedia":6}],6:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+
+  var constraintsToChrome_ = function(c) {
+    if (typeof c !== 'object' || c.mandatory || c.optional) {
+      return c;
+    }
+    var cc = {};
+    Object.keys(c).forEach(function(key) {
+      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+        return;
+      }
+      var r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
+      if (r.exact !== undefined && typeof r.exact === 'number') {
+        r.min = r.max = r.exact;
+      }
+      var oldname_ = function(prefix, name) {
+        if (prefix) {
+          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+        }
+        return (name === 'deviceId') ? 'sourceId' : name;
+      };
+      if (r.ideal !== undefined) {
+        cc.optional = cc.optional || [];
+        var oc = {};
+        if (typeof r.ideal === 'number') {
+          oc[oldname_('min', key)] = r.ideal;
+          cc.optional.push(oc);
+          oc = {};
+          oc[oldname_('max', key)] = r.ideal;
+          cc.optional.push(oc);
+        } else {
+          oc[oldname_('', key)] = r.ideal;
+          cc.optional.push(oc);
+        }
+      }
+      if (r.exact !== undefined && typeof r.exact !== 'number') {
+        cc.mandatory = cc.mandatory || {};
+        cc.mandatory[oldname_('', key)] = r.exact;
+      } else {
+        ['min', 'max'].forEach(function(mix) {
+          if (r[mix] !== undefined) {
+            cc.mandatory = cc.mandatory || {};
+            cc.mandatory[oldname_(mix, key)] = r[mix];
+          }
+        });
+      }
+    });
+    if (c.advanced) {
+      cc.optional = (cc.optional || []).concat(c.advanced);
+    }
+    return cc;
+  };
+
+  var shimConstraints_ = function(constraints, func) {
+    if (browserDetails.version >= 61) {
+      return func(constraints);
+    }
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (constraints && typeof constraints.audio === 'object') {
+      var remap = function(obj, a, b) {
+        if (a in obj && !(b in obj)) {
+          obj[b] = obj[a];
+          delete obj[a];
+        }
+      };
+      constraints = JSON.parse(JSON.stringify(constraints));
+      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
+      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
+      constraints.audio = constraintsToChrome_(constraints.audio);
+    }
+    if (constraints && typeof constraints.video === 'object') {
+      // Shim facingMode for mobile & surface pro.
+      var face = constraints.video.facingMode;
+      face = face && ((typeof face === 'object') ? face : {ideal: face});
+      var getSupportedFacingModeLies = browserDetails.version < 66;
+
+      if ((face && (face.exact === 'user' || face.exact === 'environment' ||
+                    face.ideal === 'user' || face.ideal === 'environment')) &&
+          !(navigator.mediaDevices.getSupportedConstraints &&
+            navigator.mediaDevices.getSupportedConstraints().facingMode &&
+            !getSupportedFacingModeLies)) {
+        delete constraints.video.facingMode;
+        var matches;
+        if (face.exact === 'environment' || face.ideal === 'environment') {
+          matches = ['back', 'rear'];
+        } else if (face.exact === 'user' || face.ideal === 'user') {
+          matches = ['front'];
+        }
+        if (matches) {
+          // Look for matches in label, or use last cam for back (typical).
+          return navigator.mediaDevices.enumerateDevices()
+          .then(function(devices) {
+            devices = devices.filter(function(d) {
+              return d.kind === 'videoinput';
+            });
+            var dev = devices.find(function(d) {
+              return matches.some(function(match) {
+                return d.label.toLowerCase().indexOf(match) !== -1;
+              });
+            });
+            if (!dev && devices.length && matches.indexOf('back') !== -1) {
+              dev = devices[devices.length - 1]; // more likely the back cam
+            }
+            if (dev) {
+              constraints.video.deviceId = face.exact ? {exact: dev.deviceId} :
+                                                        {ideal: dev.deviceId};
+            }
+            constraints.video = constraintsToChrome_(constraints.video);
+            logging('chrome: ' + JSON.stringify(constraints));
+            return func(constraints);
+          });
+        }
+      }
+      constraints.video = constraintsToChrome_(constraints.video);
+    }
+    logging('chrome: ' + JSON.stringify(constraints));
+    return func(constraints);
+  };
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        PermissionDeniedError: 'NotAllowedError',
+        InvalidStateError: 'NotReadableError',
+        DevicesNotFoundError: 'NotFoundError',
+        ConstraintNotSatisfiedError: 'OverconstrainedError',
+        TrackStartError: 'NotReadableError',
+        MediaDeviceFailedDueToShutdown: 'NotReadableError',
+        MediaDeviceKillSwitchOn: 'NotReadableError'
+      }[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraintName,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    shimConstraints_(constraints, function(c) {
+      navigator.webkitGetUserMedia(c, onSuccess, function(e) {
+        if (onError) {
+          onError(shimError_(e));
+        }
+      });
+    });
+  };
+
+  navigator.getUserMedia = getUserMedia_;
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      navigator.getUserMedia(constraints, resolve, reject);
+    });
+  };
+
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {
+      getUserMedia: getUserMediaPromise_,
+      enumerateDevices: function() {
+        return new Promise(function(resolve) {
+          var kinds = {audio: 'audioinput', video: 'videoinput'};
+          return window.MediaStreamTrack.getSources(function(devices) {
+            resolve(devices.map(function(device) {
+              return {label: device.label,
+                kind: kinds[device.kind],
+                deviceId: device.id,
+                groupId: ''};
+            }));
+          });
+        });
+      },
+      getSupportedConstraints: function() {
+        return {
+          deviceId: true, echoCancellation: true, facingMode: true,
+          frameRate: true, height: true, width: true
+        };
+      }
+    };
+  }
+
+  // A shim for getUserMedia method on the mediaDevices object.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (!navigator.mediaDevices.getUserMedia) {
+    navigator.mediaDevices.getUserMedia = function(constraints) {
+      return getUserMediaPromise_(constraints);
+    };
+  } else {
+    // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
+    // function which returns a Promise, it does not accept spec-style
+    // constraints.
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(cs) {
+      return shimConstraints_(cs, function(c) {
+        return origGetUserMedia(c).then(function(stream) {
+          if (c.audio && !stream.getAudioTracks().length ||
+              c.video && !stream.getVideoTracks().length) {
+            stream.getTracks().forEach(function(track) {
+              track.stop();
+            });
+            throw new DOMException('', 'NotFoundError');
+          }
+          return stream;
+        }, function(e) {
+          return Promise.reject(shimError_(e));
+        });
+      });
+    };
+  }
+
+  // Dummy devicechange event methods.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
+    navigator.mediaDevices.addEventListener = function() {
+      logging('Dummy mediaDevices.addEventListener called.');
+    };
+  }
+  if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
+    navigator.mediaDevices.removeEventListener = function() {
+      logging('Dummy mediaDevices.removeEventListener called.');
+    };
+  }
+};
+
+},{"../utils.js":13}],7:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+var utils = require('./utils');
+
+// Wraps the peerconnection event eventNameToWrap in a function
+// which returns the modified event object.
+function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  var proto = window.RTCPeerConnection.prototype;
+  var nativeAddEventListener = proto.addEventListener;
+  proto.addEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap) {
+      return nativeAddEventListener.apply(this, arguments);
+    }
+    var wrappedCallback = function(e) {
+      cb(wrapper(e));
+    };
+    this._eventMap = this._eventMap || {};
+    this._eventMap[cb] = wrappedCallback;
+    return nativeAddEventListener.apply(this, [nativeEventName,
+      wrappedCallback]);
+  };
+
+  var nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap
+        || !this._eventMap[cb]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    var unwrappedCb = this._eventMap[cb];
+    delete this._eventMap[cb];
+    return nativeRemoveEventListener.apply(this, [nativeEventName,
+      unwrappedCb]);
+  };
+
+  Object.defineProperty(proto, 'on' + eventNameToWrap, {
+    get: function() {
+      return this['_on' + eventNameToWrap];
+    },
+    set: function(cb) {
+      if (this['_on' + eventNameToWrap]) {
+        this.removeEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap]);
+        delete this['_on' + eventNameToWrap];
+      }
+      if (cb) {
+        this.addEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap] = cb);
+      }
+    }
+  });
+}
+
+module.exports = {
+  shimRTCIceCandidate: function(window) {
+    // foundation is arbitrarily chosen as an indicator for full support for
+    // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
+    if (window.RTCIceCandidate && 'foundation' in
+        window.RTCIceCandidate.prototype) {
+      return;
+    }
+
+    var NativeRTCIceCandidate = window.RTCIceCandidate;
+    window.RTCIceCandidate = function(args) {
+      // Remove the a= which shouldn't be part of the candidate string.
+      if (typeof args === 'object' && args.candidate &&
+          args.candidate.indexOf('a=') === 0) {
+        args = JSON.parse(JSON.stringify(args));
+        args.candidate = args.candidate.substr(2);
+      }
+
+      // Augment the native candidate with the parsed fields.
+      var nativeCandidate = new NativeRTCIceCandidate(args);
+      var parsedCandidate = SDPUtils.parseCandidate(args.candidate);
+      var augmentedCandidate = Object.assign(nativeCandidate,
+          parsedCandidate);
+
+      // Add a serializer that does not serialize the extra attributes.
+      augmentedCandidate.toJSON = function() {
+        return {
+          candidate: augmentedCandidate.candidate,
+          sdpMid: augmentedCandidate.sdpMid,
+          sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
+          usernameFragment: augmentedCandidate.usernameFragment,
+        };
+      };
+      return augmentedCandidate;
+    };
+
+    // Hook up the augmented candidate in onicecandidate and
+    // addEventListener('icecandidate', ...)
+    wrapPeerConnectionEvent(window, 'icecandidate', function(e) {
+      if (e.candidate) {
+        Object.defineProperty(e, 'candidate', {
+          value: new window.RTCIceCandidate(e.candidate),
+          writable: 'false'
+        });
+      }
+      return e;
+    });
+  },
+
+  // shimCreateObjectURL must be called before shimSourceObject to avoid loop.
+
+  shimCreateObjectURL: function(window) {
+    var URL = window && window.URL;
+
+    if (!(typeof window === 'object' && window.HTMLMediaElement &&
+          'srcObject' in window.HTMLMediaElement.prototype &&
+        URL.createObjectURL && URL.revokeObjectURL)) {
+      // Only shim CreateObjectURL using srcObject if srcObject exists.
+      return undefined;
+    }
+
+    var nativeCreateObjectURL = URL.createObjectURL.bind(URL);
+    var nativeRevokeObjectURL = URL.revokeObjectURL.bind(URL);
+    var streams = new Map(), newId = 0;
+
+    URL.createObjectURL = function(stream) {
+      if ('getTracks' in stream) {
+        var url = 'polyblob:' + (++newId);
+        streams.set(url, stream);
+        utils.deprecated('URL.createObjectURL(stream)',
+            'elem.srcObject = stream');
+        return url;
+      }
+      return nativeCreateObjectURL(stream);
+    };
+    URL.revokeObjectURL = function(url) {
+      nativeRevokeObjectURL(url);
+      streams.delete(url);
+    };
+
+    var dsc = Object.getOwnPropertyDescriptor(window.HTMLMediaElement.prototype,
+                                              'src');
+    Object.defineProperty(window.HTMLMediaElement.prototype, 'src', {
+      get: function() {
+        return dsc.get.apply(this);
+      },
+      set: function(url) {
+        this.srcObject = streams.get(url) || null;
+        return dsc.set.apply(this, [url]);
+      }
+    });
+
+    var nativeSetAttribute = window.HTMLMediaElement.prototype.setAttribute;
+    window.HTMLMediaElement.prototype.setAttribute = function() {
+      if (arguments.length === 2 &&
+          ('' + arguments[0]).toLowerCase() === 'src') {
+        this.srcObject = streams.get(arguments[1]) || null;
+      }
+      return nativeSetAttribute.apply(this, arguments);
+    };
+  }
+};
+
+},{"./utils":13,"sdp":2}],8:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var shimRTCPeerConnection = require('rtcpeerconnection-shim');
+
+module.exports = {
+  shimGetUserMedia: require('./getusermedia'),
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (window.RTCIceGatherer) {
+      // ORTC defines an RTCIceCandidate object but no constructor.
+      // Not implemented in Edge.
+      if (!window.RTCIceCandidate) {
+        window.RTCIceCandidate = function(args) {
+          return args;
+        };
+      }
+      // ORTC does not have a session description object but
+      // other browsers (i.e. Chrome) that will support both PC and ORTC
+      // in the future might have this defined already.
+      if (!window.RTCSessionDescription) {
+        window.RTCSessionDescription = function(args) {
+          return args;
+        };
+      }
+      // this adds an additional event listener to MediaStrackTrack that signals
+      // when a tracks enabled property was changed. Workaround for a bug in
+      // addStream, see below. No longer required in 15025+
+      if (browserDetails.version < 15025) {
+        var origMSTEnabled = Object.getOwnPropertyDescriptor(
+            window.MediaStreamTrack.prototype, 'enabled');
+        Object.defineProperty(window.MediaStreamTrack.prototype, 'enabled', {
+          set: function(value) {
+            origMSTEnabled.set.call(this, value);
+            var ev = new Event('enabled');
+            ev.enabled = value;
+            this.dispatchEvent(ev);
+          }
+        });
+      }
+    }
+
+    // ORTC defines the DTMF sender a bit different.
+    // https://github.com/w3c/ortc/issues/714
+    if (window.RTCRtpSender && !('dtmf' in window.RTCRtpSender.prototype)) {
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = new window.RTCDtmfSender(this);
+            } else if (this.track.kind === 'video') {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+
+    window.RTCPeerConnection =
+        shimRTCPeerConnection(window, browserDetails.version);
+  },
+  shimReplaceTrack: function(window) {
+    // ORTC has replaceTrack -- https://github.com/w3c/ortc/issues/614
+    if (window.RTCRtpSender &&
+        !('replaceTrack' in window.RTCRtpSender.prototype)) {
+      window.RTCRtpSender.prototype.replaceTrack =
+          window.RTCRtpSender.prototype.setTrack;
+    }
+  }
+};
+
+},{"../utils":13,"./getusermedia":9,"rtcpeerconnection-shim":1}],9:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+// Expose public methods.
+module.exports = function(window) {
+  var navigator = window && window.navigator;
+
+  var shimError_ = function(e) {
+    return {
+      name: {PermissionDeniedError: 'NotAllowedError'}[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name;
+      }
+    };
+  };
+
+  // getUserMedia error shim.
+  var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+      bind(navigator.mediaDevices);
+  navigator.mediaDevices.getUserMedia = function(c) {
+    return origGetUserMedia(c).catch(function(e) {
+      return Promise.reject(shimError_(e));
+    });
+  };
+};
+
+},{}],10:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+
+var firefoxShim = {
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+            this.removeEventListener('addstream', this._ontrackpoly);
+          }
+          this.addEventListener('track', this._ontrack = f);
+          this.addEventListener('addstream', this._ontrackpoly = function(e) {
+            e.stream.getTracks().forEach(function(track) {
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = {track: track};
+              event.transceiver = {receiver: event.receiver};
+              event.streams = [e.stream];
+              this.dispatchEvent(event);
+            }.bind(this));
+          }.bind(this));
+        }
+      });
+    }
+    if (typeof window === 'object' && window.RTCTrackEvent &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        !('transceiver' in window.RTCTrackEvent.prototype)) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this.mozSrcObject;
+          },
+          set: function(stream) {
+            this.mozSrcObject = stream;
+          }
+        });
+      }
+    }
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (typeof window !== 'object' || !(window.RTCPeerConnection ||
+        window.mozRTCPeerConnection)) {
+      return; // probably media.peerconnection.enabled=false in about:config
+    }
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (browserDetails.version < 38) {
+          // .urls is not supported in FF < 38.
+          // create RTCIceServers with a single url.
+          if (pcConfig && pcConfig.iceServers) {
+            var newIceServers = [];
+            for (var i = 0; i < pcConfig.iceServers.length; i++) {
+              var server = pcConfig.iceServers[i];
+              if (server.hasOwnProperty('urls')) {
+                for (var j = 0; j < server.urls.length; j++) {
+                  var newServer = {
+                    url: server.urls[j]
+                  };
+                  if (server.urls[j].indexOf('turn') === 0) {
+                    newServer.username = server.username;
+                    newServer.credential = server.credential;
+                  }
+                  newIceServers.push(newServer);
+                }
+              } else {
+                newIceServers.push(pcConfig.iceServers[i]);
+              }
+            }
+            pcConfig.iceServers = newIceServers;
+          }
+        }
+        return new window.mozRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.mozRTCPeerConnection.prototype;
+
+      // wrap static methods. Currently just generateCertificate.
+      if (window.mozRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.mozRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+
+      window.RTCSessionDescription = window.mozRTCSessionDescription;
+      window.RTCIceCandidate = window.mozRTCIceCandidate;
+    }
+
+    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+
+    // shim getStats with maplike support
+    var makeMapStats = function(stats) {
+      var map = new Map();
+      Object.keys(stats).forEach(function(key) {
+        map.set(key, stats[key]);
+        map[key] = stats[key];
+      });
+      return map;
+    };
+
+    var modernStatsTypes = {
+      inboundrtp: 'inbound-rtp',
+      outboundrtp: 'outbound-rtp',
+      candidatepair: 'candidate-pair',
+      localcandidate: 'local-candidate',
+      remotecandidate: 'remote-candidate'
+    };
+
+    var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(
+      selector,
+      onSucc,
+      onErr
+    ) {
+      return nativeGetStats.apply(this, [selector || null])
+        .then(function(stats) {
+          if (browserDetails.version < 48) {
+            stats = makeMapStats(stats);
+          }
+          if (browserDetails.version < 53 && !onSucc) {
+            // Shim only promise getStats with spec-hyphens in type names
+            // Leave callback version alone; misc old uses of forEach before Map
+            try {
+              stats.forEach(function(stat) {
+                stat.type = modernStatsTypes[stat.type] || stat.type;
+              });
+            } catch (e) {
+              if (e.name !== 'TypeError') {
+                throw e;
+              }
+              // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
+              stats.forEach(function(stat, i) {
+                stats.set(i, Object.assign({}, stat, {
+                  type: modernStatsTypes[stat.type] || stat.type
+                }));
+              });
+            }
+          }
+          return stats;
+        })
+        .then(onSucc, onErr);
+    };
+  },
+
+  shimRemoveStream: function(window) {
+    if (!window.RTCPeerConnection ||
+        'removeStream' in window.RTCPeerConnection.prototype) {
+      return;
+    }
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      utils.deprecated('removeStream', 'removeTrack');
+      this.getSenders().forEach(function(sender) {
+        if (sender.track && stream.getTracks().indexOf(sender.track) !== -1) {
+          pc.removeTrack(sender);
+        }
+      });
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimOnTrack: firefoxShim.shimOnTrack,
+  shimSourceObject: firefoxShim.shimSourceObject,
+  shimPeerConnection: firefoxShim.shimPeerConnection,
+  shimRemoveStream: firefoxShim.shimRemoveStream,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils":13,"./getusermedia":11}],11:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+  var MediaStreamTrack = window && window.MediaStreamTrack;
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        InternalError: 'NotReadableError',
+        NotSupportedError: 'TypeError',
+        PermissionDeniedError: 'NotAllowedError',
+        SecurityError: 'NotAllowedError'
+      }[e.name] || e.name,
+      message: {
+        'The operation is insecure.': 'The request is not allowed by the ' +
+        'user agent or the platform in the current context.'
+      }[e.message] || e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  // getUserMedia constraints shim.
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    var constraintsToFF37_ = function(c) {
+      if (typeof c !== 'object' || c.require) {
+        return c;
+      }
+      var require = [];
+      Object.keys(c).forEach(function(key) {
+        if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+          return;
+        }
+        var r = c[key] = (typeof c[key] === 'object') ?
+            c[key] : {ideal: c[key]};
+        if (r.min !== undefined ||
+            r.max !== undefined || r.exact !== undefined) {
+          require.push(key);
+        }
+        if (r.exact !== undefined) {
+          if (typeof r.exact === 'number') {
+            r. min = r.max = r.exact;
+          } else {
+            c[key] = r.exact;
+          }
+          delete r.exact;
+        }
+        if (r.ideal !== undefined) {
+          c.advanced = c.advanced || [];
+          var oc = {};
+          if (typeof r.ideal === 'number') {
+            oc[key] = {min: r.ideal, max: r.ideal};
+          } else {
+            oc[key] = r.ideal;
+          }
+          c.advanced.push(oc);
+          delete r.ideal;
+          if (!Object.keys(r).length) {
+            delete c[key];
+          }
+        }
+      });
+      if (require.length) {
+        c.require = require;
+      }
+      return c;
+    };
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (browserDetails.version < 38) {
+      logging('spec: ' + JSON.stringify(constraints));
+      if (constraints.audio) {
+        constraints.audio = constraintsToFF37_(constraints.audio);
+      }
+      if (constraints.video) {
+        constraints.video = constraintsToFF37_(constraints.video);
+      }
+      logging('ff37: ' + JSON.stringify(constraints));
+    }
+    return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
+      onError(shimError_(e));
+    });
+  };
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      getUserMedia_(constraints, resolve, reject);
+    });
+  };
+
+  // Shim for mediaDevices on older versions.
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
+      addEventListener: function() { },
+      removeEventListener: function() { }
+    };
+  }
+  navigator.mediaDevices.enumerateDevices =
+      navigator.mediaDevices.enumerateDevices || function() {
+        return new Promise(function(resolve) {
+          var infos = [
+            {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
+            {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
+          ];
+          resolve(infos);
+        });
+      };
+
+  if (browserDetails.version < 41) {
+    // Work around http://bugzil.la/1169665
+    var orgEnumerateDevices =
+        navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
+    navigator.mediaDevices.enumerateDevices = function() {
+      return orgEnumerateDevices().then(undefined, function(e) {
+        if (e.name === 'NotFoundError') {
+          return [];
+        }
+        throw e;
+      });
+    };
+  }
+  if (browserDetails.version < 49) {
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      return origGetUserMedia(c).then(function(stream) {
+        // Work around https://bugzil.la/802326
+        if (c.audio && !stream.getAudioTracks().length ||
+            c.video && !stream.getVideoTracks().length) {
+          stream.getTracks().forEach(function(track) {
+            track.stop();
+          });
+          throw new DOMException('The object can not be found here.',
+                                 'NotFoundError');
+        }
+        return stream;
+      }, function(e) {
+        return Promise.reject(shimError_(e));
+      });
+    };
+  }
+  if (!(browserDetails.version > 55 &&
+      'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
+    var remap = function(obj, a, b) {
+      if (a in obj && !(b in obj)) {
+        obj[b] = obj[a];
+        delete obj[a];
+      }
+    };
+
+    var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      if (typeof c === 'object' && typeof c.audio === 'object') {
+        c = JSON.parse(JSON.stringify(c));
+        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
+        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
+      }
+      return nativeGetUserMedia(c);
+    };
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
+      var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
+      MediaStreamTrack.prototype.getSettings = function() {
+        var obj = nativeGetSettings.apply(this, arguments);
+        remap(obj, 'mozAutoGainControl', 'autoGainControl');
+        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
+        return obj;
+      };
+    }
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
+      var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
+      MediaStreamTrack.prototype.applyConstraints = function(c) {
+        if (this.kind === 'audio' && typeof c === 'object') {
+          c = JSON.parse(JSON.stringify(c));
+          remap(c, 'autoGainControl', 'mozAutoGainControl');
+          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
+        }
+        return nativeApplyConstraints.apply(this, [c]);
+      };
+    }
+  }
+  navigator.getUserMedia = function(constraints, onSuccess, onError) {
+    if (browserDetails.version < 44) {
+      return getUserMedia_(constraints, onSuccess, onError);
+    }
+    // Replace Firefox 44+'s deprecation warning with unprefixed version.
+    utils.deprecated('navigator.getUserMedia',
+        'navigator.mediaDevices.getUserMedia');
+    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
+  };
+};
+
+},{"../utils":13}],12:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+'use strict';
+var utils = require('../utils');
+
+var safariShim = {
+  // TODO: DrAlex, should be here, double check against LayoutTests
+
+  // TODO: once the back-end for the mac port is done, add.
+  // TODO: check for webkitGTK+
+  // shimPeerConnection: function() { },
+
+  shimLocalStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getLocalStreams = function() {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        return this._localStreams;
+      };
+    }
+    if (!('getStreamById' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getStreamById = function(id) {
+        var result = null;
+        if (this._localStreams) {
+          this._localStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        if (this._remoteStreams) {
+          this._remoteStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        return result;
+      };
+    }
+    if (!('addStream' in window.RTCPeerConnection.prototype)) {
+      var _addTrack = window.RTCPeerConnection.prototype.addTrack;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        if (this._localStreams.indexOf(stream) === -1) {
+          this._localStreams.push(stream);
+        }
+        var self = this;
+        stream.getTracks().forEach(function(track) {
+          _addTrack.call(self, track, stream);
+        });
+      };
+
+      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+        if (stream) {
+          if (!this._localStreams) {
+            this._localStreams = [stream];
+          } else if (this._localStreams.indexOf(stream) === -1) {
+            this._localStreams.push(stream);
+          }
+        }
+        return _addTrack.call(this, track, stream);
+      };
+    }
+    if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        var index = this._localStreams.indexOf(stream);
+        if (index === -1) {
+          return;
+        }
+        this._localStreams.splice(index, 1);
+        var self = this;
+        var tracks = stream.getTracks();
+        this.getSenders().forEach(function(sender) {
+          if (tracks.indexOf(sender.track) !== -1) {
+            self.removeTrack(sender);
+          }
+        });
+      };
+    }
+  },
+  shimRemoteStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getRemoteStreams = function() {
+        return this._remoteStreams ? this._remoteStreams : [];
+      };
+    }
+    if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
+        get: function() {
+          return this._onaddstream;
+        },
+        set: function(f) {
+          if (this._onaddstream) {
+            this.removeEventListener('addstream', this._onaddstream);
+            this.removeEventListener('track', this._onaddstreampoly);
+          }
+          this.addEventListener('addstream', this._onaddstream = f);
+          this.addEventListener('track', this._onaddstreampoly = function(e) {
+            var stream = e.streams[0];
+            if (!this._remoteStreams) {
+              this._remoteStreams = [];
+            }
+            if (this._remoteStreams.indexOf(stream) >= 0) {
+              return;
+            }
+            this._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = e.streams[0];
+            this.dispatchEvent(event);
+          }.bind(this));
+        }
+      });
+    }
+  },
+  shimCallbacksAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    var prototype = window.RTCPeerConnection.prototype;
+    var createOffer = prototype.createOffer;
+    var createAnswer = prototype.createAnswer;
+    var setLocalDescription = prototype.setLocalDescription;
+    var setRemoteDescription = prototype.setRemoteDescription;
+    var addIceCandidate = prototype.addIceCandidate;
+
+    prototype.createOffer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createOffer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    prototype.createAnswer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createAnswer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    var withCallback = function(description, successCallback, failureCallback) {
+      var promise = setLocalDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setLocalDescription = withCallback;
+
+    withCallback = function(description, successCallback, failureCallback) {
+      var promise = setRemoteDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setRemoteDescription = withCallback;
+
+    withCallback = function(candidate, successCallback, failureCallback) {
+      var promise = addIceCandidate.apply(this, [candidate]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.addIceCandidate = withCallback;
+  },
+  shimGetUserMedia: function(window) {
+    var navigator = window && window.navigator;
+
+    if (!navigator.getUserMedia) {
+      if (navigator.webkitGetUserMedia) {
+        navigator.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
+      } else if (navigator.mediaDevices &&
+          navigator.mediaDevices.getUserMedia) {
+        navigator.getUserMedia = function(constraints, cb, errcb) {
+          navigator.mediaDevices.getUserMedia(constraints)
+          .then(cb, errcb);
+        }.bind(navigator);
+      }
+    }
+  },
+  shimRTCIceServerUrls: function(window) {
+    // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+    var OrigPeerConnection = window.RTCPeerConnection;
+    window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+      if (pcConfig && pcConfig.iceServers) {
+        var newIceServers = [];
+        for (var i = 0; i < pcConfig.iceServers.length; i++) {
+          var server = pcConfig.iceServers[i];
+          if (!server.hasOwnProperty('urls') &&
+              server.hasOwnProperty('url')) {
+            utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+            server = JSON.parse(JSON.stringify(server));
+            server.urls = server.url;
+            delete server.url;
+            newIceServers.push(server);
+          } else {
+            newIceServers.push(pcConfig.iceServers[i]);
+          }
+        }
+        pcConfig.iceServers = newIceServers;
+      }
+      return new OrigPeerConnection(pcConfig, pcConstraints);
+    };
+    window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+    // wrap static methods. Currently just generateCertificate.
+    if ('generateCertificate' in window.RTCPeerConnection) {
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+  },
+  shimTrackEventTransceiver: function(window) {
+    // Add event.transceiver member over deprecated event.receiver
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        // can't check 'transceiver' in window.RTCTrackEvent.prototype, as it is
+        // defined for some reason even when window.RTCTransceiver is not.
+        !window.RTCTransceiver) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimCreateOfferLegacy: function(window) {
+    var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+    window.RTCPeerConnection.prototype.createOffer = function(offerOptions) {
+      var pc = this;
+      if (offerOptions) {
+        var audioTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'audio';
+        });
+        if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
+          if (audioTransceiver.direction === 'sendrecv') {
+            audioTransceiver.setDirection('sendonly');
+          } else if (audioTransceiver.direction === 'recvonly') {
+            audioTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveAudio === true &&
+            !audioTransceiver) {
+          pc.addTransceiver('audio');
+        }
+
+        var videoTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'video';
+        });
+        if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
+          if (videoTransceiver.direction === 'sendrecv') {
+            videoTransceiver.setDirection('sendonly');
+          } else if (videoTransceiver.direction === 'recvonly') {
+            videoTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveVideo === true &&
+            !videoTransceiver) {
+          pc.addTransceiver('video');
+        }
+      }
+      return origCreateOffer.apply(pc, arguments);
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimCallbacksAPI: safariShim.shimCallbacksAPI,
+  shimLocalStreamsAPI: safariShim.shimLocalStreamsAPI,
+  shimRemoteStreamsAPI: safariShim.shimRemoteStreamsAPI,
+  shimGetUserMedia: safariShim.shimGetUserMedia,
+  shimRTCIceServerUrls: safariShim.shimRTCIceServerUrls,
+  shimTrackEventTransceiver: safariShim.shimTrackEventTransceiver,
+  shimCreateOfferLegacy: safariShim.shimCreateOfferLegacy
+  // TODO
+  // shimPeerConnection: safariShim.shimPeerConnection
+};
+
+},{"../utils":13}],13:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var logDisabled_ = true;
+var deprecationWarnings_ = true;
+
+// Utility methods.
+var utils = {
+  disableLog: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    logDisabled_ = bool;
+    return (bool) ? 'adapter.js logging disabled' :
+        'adapter.js logging enabled';
+  },
+
+  /**
+   * Disable or enable deprecation warnings
+   * @param {!boolean} bool set to true to disable warnings.
+   */
+  disableWarnings: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    deprecationWarnings_ = !bool;
+    return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
+  },
+
+  log: function() {
+    if (typeof window === 'object') {
+      if (logDisabled_) {
+        return;
+      }
+      if (typeof console !== 'undefined' && typeof console.log === 'function') {
+        console.log.apply(console, arguments);
+      }
+    }
+  },
+
+  /**
+   * Shows a deprecation warning suggesting the modern and spec-compatible API.
+   */
+  deprecated: function(oldMethod, newMethod) {
+    if (!deprecationWarnings_) {
+      return;
+    }
+    console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
+        ' instead.');
+  },
+
+  /**
+   * Extract browser version out of the provided user agent string.
+   *
+   * @param {!string} uastring userAgent string.
+   * @param {!string} expr Regular expression used as match criteria.
+   * @param {!number} pos position in the version string to be returned.
+   * @return {!number} browser version.
+   */
+  extractVersion: function(uastring, expr, pos) {
+    var match = uastring.match(expr);
+    return match && match.length >= pos && parseInt(match[pos], 10);
+  },
+
+  /**
+   * Browser detector.
+   *
+   * @return {object} result containing browser and version
+   *     properties.
+   */
+  detectBrowser: function(window) {
+    var navigator = window && window.navigator;
+
+    // Returned result object.
+    var result = {};
+    result.browser = null;
+    result.version = null;
+
+    // Fail early if it's not a browser
+    if (typeof window === 'undefined' || !window.navigator) {
+      result.browser = 'Not a browser.';
+      return result;
+    }
+
+    // Firefox.
+    if (navigator.mozGetUserMedia) {
+      result.browser = 'firefox';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Firefox\/(\d+)\./, 1);
+    } else if (navigator.webkitGetUserMedia) {
+      // Chrome, Chromium, Webview, Opera, all use the chrome shim for now
+      if (window.webkitRTCPeerConnection) {
+        result.browser = 'chrome';
+        result.version = this.extractVersion(navigator.userAgent,
+          /Chrom(e|ium)\/(\d+)\./, 2);
+      } else { // Safari (in an unpublished version) or unknown webkit-based.
+        if (navigator.userAgent.match(/Version\/(\d+).(\d+)/)) {
+          result.browser = 'safari';
+          result.version = this.extractVersion(navigator.userAgent,
+            /AppleWebKit\/(\d+)\./, 1);
+        } else { // unknown webkit-based browser.
+          result.browser = 'Unsupported webkit-based browser ' +
+              'with GUM support but no WebRTC support.';
+          return result;
+        }
+      }
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) { // Edge.
+      result.browser = 'edge';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Edge\/(\d+).(\d+)$/, 2);
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) {
+        // Safari, with webkitGetUserMedia removed.
+      result.browser = 'safari';
+      result.version = this.extractVersion(navigator.userAgent,
+          /AppleWebKit\/(\d+)\./, 1);
+    } else { // Default fallthrough: not supported.
+      result.browser = 'Not a supported browser.';
+      return result;
+    }
+
+    return result;
+  },
+
+};
+
+// Export.
+module.exports = {
+  log: utils.log,
+  deprecated: utils.deprecated,
+  disableLog: utils.disableLog,
+  disableWarnings: utils.disableWarnings,
+  extractVersion: utils.extractVersion,
+  shimCreateObjectURL: utils.shimCreateObjectURL,
+  detectBrowser: utils.detectBrowser.bind(utils)
+};
+
+},{}]},{},[3])(3)
+});

+ 4471 - 0
support/client/lib/vwf/view/webrtc/dist/adapter.js

@@ -0,0 +1,4471 @@
+(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.adapter = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+
+function writeMediaSection(transceiver, caps, type, stream, dtlsRole) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : dtlsRole || 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+}
+
+// Edge does not like
+// 1) stun: filtered after 14393 unless ?transport=udp is present
+// 2) turn: that does not have all of turn:host:port?transport=udp
+// 3) turn: with ipv6 addresses
+// 4) turn: occurring muliple times
+function filterIceServers(iceServers, edgeVersion) {
+  var hasTurn = false;
+  iceServers = JSON.parse(JSON.stringify(iceServers));
+  return iceServers.filter(function(server) {
+    if (server && (server.urls || server.url)) {
+      var urls = server.urls || server.url;
+      if (server.url && !server.urls) {
+        console.warn('RTCIceServer.url is deprecated! Use urls instead.');
+      }
+      var isString = typeof urls === 'string';
+      if (isString) {
+        urls = [urls];
+      }
+      urls = urls.filter(function(url) {
+        var validTurn = url.indexOf('turn:') === 0 &&
+            url.indexOf('transport=udp') !== -1 &&
+            url.indexOf('turn:[') === -1 &&
+            !hasTurn;
+
+        if (validTurn) {
+          hasTurn = true;
+          return true;
+        }
+        return url.indexOf('stun:') === 0 && edgeVersion >= 14393 &&
+            url.indexOf('?transport=udp') === -1;
+      });
+
+      delete server.url;
+      server.urls = isString ? urls[0] : urls;
+      return !!urls.length;
+    }
+    return false;
+  });
+}
+
+// Determines the intersection of local and remote capabilities.
+function getCommonCapabilities(localCapabilities, remoteCapabilities) {
+  var commonCapabilities = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: []
+  };
+
+  var findCodecByPayloadType = function(pt, codecs) {
+    pt = parseInt(pt, 10);
+    for (var i = 0; i < codecs.length; i++) {
+      if (codecs[i].payloadType === pt ||
+          codecs[i].preferredPayloadType === pt) {
+        return codecs[i];
+      }
+    }
+  };
+
+  var rtxCapabilityMatches = function(lRtx, rRtx, lCodecs, rCodecs) {
+    var lCodec = findCodecByPayloadType(lRtx.parameters.apt, lCodecs);
+    var rCodec = findCodecByPayloadType(rRtx.parameters.apt, rCodecs);
+    return lCodec && rCodec &&
+        lCodec.name.toLowerCase() === rCodec.name.toLowerCase();
+  };
+
+  localCapabilities.codecs.forEach(function(lCodec) {
+    for (var i = 0; i < remoteCapabilities.codecs.length; i++) {
+      var rCodec = remoteCapabilities.codecs[i];
+      if (lCodec.name.toLowerCase() === rCodec.name.toLowerCase() &&
+          lCodec.clockRate === rCodec.clockRate) {
+        if (lCodec.name.toLowerCase() === 'rtx' &&
+            lCodec.parameters && rCodec.parameters.apt) {
+          // for RTX we need to find the local rtx that has a apt
+          // which points to the same local codec as the remote one.
+          if (!rtxCapabilityMatches(lCodec, rCodec,
+              localCapabilities.codecs, remoteCapabilities.codecs)) {
+            continue;
+          }
+        }
+        rCodec = JSON.parse(JSON.stringify(rCodec)); // deepcopy
+        // number of channels is the highest common number of channels
+        rCodec.numChannels = Math.min(lCodec.numChannels,
+            rCodec.numChannels);
+        // push rCodec so we reply with offerer payload type
+        commonCapabilities.codecs.push(rCodec);
+
+        // determine common feedback mechanisms
+        rCodec.rtcpFeedback = rCodec.rtcpFeedback.filter(function(fb) {
+          for (var j = 0; j < lCodec.rtcpFeedback.length; j++) {
+            if (lCodec.rtcpFeedback[j].type === fb.type &&
+                lCodec.rtcpFeedback[j].parameter === fb.parameter) {
+              return true;
+            }
+          }
+          return false;
+        });
+        // FIXME: also need to determine .parameters
+        //  see https://github.com/openpeer/ortc/issues/569
+        break;
+      }
+    }
+  });
+
+  localCapabilities.headerExtensions.forEach(function(lHeaderExtension) {
+    for (var i = 0; i < remoteCapabilities.headerExtensions.length;
+         i++) {
+      var rHeaderExtension = remoteCapabilities.headerExtensions[i];
+      if (lHeaderExtension.uri === rHeaderExtension.uri) {
+        commonCapabilities.headerExtensions.push(rHeaderExtension);
+        break;
+      }
+    }
+  });
+
+  // FIXME: fecMechanisms
+  return commonCapabilities;
+}
+
+// is action=setLocalDescription with type allowed in signalingState
+function isActionAllowedInSignalingState(action, type, signalingState) {
+  return {
+    offer: {
+      setLocalDescription: ['stable', 'have-local-offer'],
+      setRemoteDescription: ['stable', 'have-remote-offer']
+    },
+    answer: {
+      setLocalDescription: ['have-remote-offer', 'have-local-pranswer'],
+      setRemoteDescription: ['have-local-offer', 'have-remote-pranswer']
+    }
+  }[type][action].indexOf(signalingState) !== -1;
+}
+
+function maybeAddCandidate(iceTransport, candidate) {
+  // Edge's internal representation adds some fields therefore
+  // not all fieldѕ are taken into account.
+  var alreadyAdded = iceTransport.getRemoteCandidates()
+      .find(function(remoteCandidate) {
+        return candidate.foundation === remoteCandidate.foundation &&
+            candidate.ip === remoteCandidate.ip &&
+            candidate.port === remoteCandidate.port &&
+            candidate.priority === remoteCandidate.priority &&
+            candidate.protocol === remoteCandidate.protocol &&
+            candidate.type === remoteCandidate.type;
+      });
+  if (!alreadyAdded) {
+    iceTransport.addRemoteCandidate(candidate);
+  }
+  return !alreadyAdded;
+}
+
+module.exports = function(window, edgeVersion) {
+  var RTCPeerConnection = function(config) {
+    var self = this;
+
+    var _eventTarget = document.createDocumentFragment();
+    ['addEventListener', 'removeEventListener', 'dispatchEvent']
+        .forEach(function(method) {
+          self[method] = _eventTarget[method].bind(_eventTarget);
+        });
+
+    this.onicecandidate = null;
+    this.onaddstream = null;
+    this.ontrack = null;
+    this.onremovestream = null;
+    this.onsignalingstatechange = null;
+    this.oniceconnectionstatechange = null;
+    this.onicegatheringstatechange = null;
+    this.onnegotiationneeded = null;
+    this.ondatachannel = null;
+    this.canTrickleIceCandidates = null;
+
+    this.needNegotiation = false;
+
+    this.localStreams = [];
+    this.remoteStreams = [];
+
+    this.localDescription = null;
+    this.remoteDescription = null;
+
+    this.signalingState = 'stable';
+    this.iceConnectionState = 'new';
+    this.iceGatheringState = 'new';
+
+    config = JSON.parse(JSON.stringify(config || {}));
+
+    this.usingBundle = config.bundlePolicy === 'max-bundle';
+    if (config.rtcpMuxPolicy === 'negotiate') {
+      var e = new Error('rtcpMuxPolicy \'negotiate\' is not supported');
+      e.name = 'NotSupportedError';
+      throw(e);
+    } else if (!config.rtcpMuxPolicy) {
+      config.rtcpMuxPolicy = 'require';
+    }
+
+    switch (config.iceTransportPolicy) {
+      case 'all':
+      case 'relay':
+        break;
+      default:
+        config.iceTransportPolicy = 'all';
+        break;
+    }
+
+    switch (config.bundlePolicy) {
+      case 'balanced':
+      case 'max-compat':
+      case 'max-bundle':
+        break;
+      default:
+        config.bundlePolicy = 'balanced';
+        break;
+    }
+
+    config.iceServers = filterIceServers(config.iceServers || [], edgeVersion);
+
+    this._iceGatherers = [];
+    if (config.iceCandidatePoolSize) {
+      for (var i = config.iceCandidatePoolSize; i > 0; i--) {
+        this._iceGatherers = new window.RTCIceGatherer({
+          iceServers: config.iceServers,
+          gatherPolicy: config.iceTransportPolicy
+        });
+      }
+    } else {
+      config.iceCandidatePoolSize = 0;
+    }
+
+    this._config = config;
+
+    // per-track iceGathers, iceTransports, dtlsTransports, rtpSenders, ...
+    // everything that is needed to describe a SDP m-line.
+    this.transceivers = [];
+
+    this._sdpSessionId = SDPUtils.generateSessionId();
+    this._sdpSessionVersion = 0;
+
+    this._dtlsRole = undefined; // role for a=setup to use in answers.
+  };
+
+  RTCPeerConnection.prototype._emitGatheringStateChange = function() {
+    var event = new Event('icegatheringstatechange');
+    this.dispatchEvent(event);
+    if (typeof this.onicegatheringstatechange === 'function') {
+      this.onicegatheringstatechange(event);
+    }
+  };
+
+  RTCPeerConnection.prototype.getConfiguration = function() {
+    return this._config;
+  };
+
+  RTCPeerConnection.prototype.getLocalStreams = function() {
+    return this.localStreams;
+  };
+
+  RTCPeerConnection.prototype.getRemoteStreams = function() {
+    return this.remoteStreams;
+  };
+
+  // internal helper to create a transceiver object.
+  // (whih is not yet the same as the WebRTC 1.0 transceiver)
+  RTCPeerConnection.prototype._createTransceiver = function(kind) {
+    var hasBundleTransport = this.transceivers.length > 0;
+    var transceiver = {
+      track: null,
+      iceGatherer: null,
+      iceTransport: null,
+      dtlsTransport: null,
+      localCapabilities: null,
+      remoteCapabilities: null,
+      rtpSender: null,
+      rtpReceiver: null,
+      kind: kind,
+      mid: null,
+      sendEncodingParameters: null,
+      recvEncodingParameters: null,
+      stream: null,
+      wantReceive: true
+    };
+    if (this.usingBundle && hasBundleTransport) {
+      transceiver.iceTransport = this.transceivers[0].iceTransport;
+      transceiver.dtlsTransport = this.transceivers[0].dtlsTransport;
+    } else {
+      var transports = this._createIceAndDtlsTransports();
+      transceiver.iceTransport = transports.iceTransport;
+      transceiver.dtlsTransport = transports.dtlsTransport;
+    }
+    this.transceivers.push(transceiver);
+    return transceiver;
+  };
+
+  RTCPeerConnection.prototype.addTrack = function(track, stream) {
+    var transceiver;
+    for (var i = 0; i < this.transceivers.length; i++) {
+      if (!this.transceivers[i].track &&
+          this.transceivers[i].kind === track.kind) {
+        transceiver = this.transceivers[i];
+      }
+    }
+    if (!transceiver) {
+      transceiver = this._createTransceiver(track.kind);
+    }
+
+    this._maybeFireNegotiationNeeded();
+
+    if (this.localStreams.indexOf(stream) === -1) {
+      this.localStreams.push(stream);
+    }
+
+    transceiver.track = track;
+    transceiver.stream = stream;
+    transceiver.rtpSender = new window.RTCRtpSender(track,
+        transceiver.dtlsTransport);
+    return transceiver.rtpSender;
+  };
+
+  RTCPeerConnection.prototype.addStream = function(stream) {
+    var self = this;
+    if (edgeVersion >= 15025) {
+      stream.getTracks().forEach(function(track) {
+        self.addTrack(track, stream);
+      });
+    } else {
+      // Clone is necessary for local demos mostly, attaching directly
+      // to two different senders does not work (build 10547).
+      // Fixed in 15025 (or earlier)
+      var clonedStream = stream.clone();
+      stream.getTracks().forEach(function(track, idx) {
+        var clonedTrack = clonedStream.getTracks()[idx];
+        track.addEventListener('enabled', function(event) {
+          clonedTrack.enabled = event.enabled;
+        });
+      });
+      clonedStream.getTracks().forEach(function(track) {
+        self.addTrack(track, clonedStream);
+      });
+    }
+  };
+
+  RTCPeerConnection.prototype.removeStream = function(stream) {
+    var idx = this.localStreams.indexOf(stream);
+    if (idx > -1) {
+      this.localStreams.splice(idx, 1);
+      this._maybeFireNegotiationNeeded();
+    }
+  };
+
+  RTCPeerConnection.prototype.getSenders = function() {
+    return this.transceivers.filter(function(transceiver) {
+      return !!transceiver.rtpSender;
+    })
+    .map(function(transceiver) {
+      return transceiver.rtpSender;
+    });
+  };
+
+  RTCPeerConnection.prototype.getReceivers = function() {
+    return this.transceivers.filter(function(transceiver) {
+      return !!transceiver.rtpReceiver;
+    })
+    .map(function(transceiver) {
+      return transceiver.rtpReceiver;
+    });
+  };
+
+
+  RTCPeerConnection.prototype._createIceGatherer = function(sdpMLineIndex,
+      usingBundle) {
+    var self = this;
+    if (usingBundle && sdpMLineIndex > 0) {
+      return this.transceivers[0].iceGatherer;
+    } else if (this._iceGatherers.length) {
+      return this._iceGatherers.shift();
+    }
+    var iceGatherer = new window.RTCIceGatherer({
+      iceServers: this._config.iceServers,
+      gatherPolicy: this._config.iceTransportPolicy
+    });
+    Object.defineProperty(iceGatherer, 'state',
+        {value: 'new', writable: true}
+    );
+
+    this.transceivers[sdpMLineIndex].candidates = [];
+    this.transceivers[sdpMLineIndex].bufferCandidates = function(event) {
+      var end = !event.candidate || Object.keys(event.candidate).length === 0;
+      // polyfill since RTCIceGatherer.state is not implemented in
+      // Edge 10547 yet.
+      iceGatherer.state = end ? 'completed' : 'gathering';
+      if (self.transceivers[sdpMLineIndex].candidates !== null) {
+        self.transceivers[sdpMLineIndex].candidates.push(event.candidate);
+      }
+    };
+    iceGatherer.addEventListener('localcandidate',
+      this.transceivers[sdpMLineIndex].bufferCandidates);
+    return iceGatherer;
+  };
+
+  // start gathering from an RTCIceGatherer.
+  RTCPeerConnection.prototype._gather = function(mid, sdpMLineIndex) {
+    var self = this;
+    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
+    if (iceGatherer.onlocalcandidate) {
+      return;
+    }
+    var candidates = this.transceivers[sdpMLineIndex].candidates;
+    this.transceivers[sdpMLineIndex].candidates = null;
+    iceGatherer.removeEventListener('localcandidate',
+      this.transceivers[sdpMLineIndex].bufferCandidates);
+    iceGatherer.onlocalcandidate = function(evt) {
+      if (self.usingBundle && sdpMLineIndex > 0) {
+        // if we know that we use bundle we can drop candidates with
+        // ѕdpMLineIndex > 0. If we don't do this then our state gets
+        // confused since we dispose the extra ice gatherer.
+        return;
+      }
+      var event = new Event('icecandidate');
+      event.candidate = {sdpMid: mid, sdpMLineIndex: sdpMLineIndex};
+
+      var cand = evt.candidate;
+      // Edge emits an empty object for RTCIceCandidateComplete‥
+      var end = !cand || Object.keys(cand).length === 0;
+      if (end) {
+        // polyfill since RTCIceGatherer.state is not implemented in
+        // Edge 10547 yet.
+        if (iceGatherer.state === 'new' || iceGatherer.state === 'gathering') {
+          iceGatherer.state = 'completed';
+        }
+      } else {
+        if (iceGatherer.state === 'new') {
+          iceGatherer.state = 'gathering';
+        }
+        // RTCIceCandidate doesn't have a component, needs to be added
+        cand.component = 1;
+        event.candidate.candidate = SDPUtils.writeCandidate(cand);
+      }
+
+      // update local description.
+      var sections = SDPUtils.splitSections(self.localDescription.sdp);
+      if (!end) {
+        sections[event.candidate.sdpMLineIndex + 1] +=
+            'a=' + event.candidate.candidate + '\r\n';
+      } else {
+        sections[event.candidate.sdpMLineIndex + 1] +=
+            'a=end-of-candidates\r\n';
+      }
+      self.localDescription.sdp = sections.join('');
+      var complete = self.transceivers.every(function(transceiver) {
+        return transceiver.iceGatherer &&
+            transceiver.iceGatherer.state === 'completed';
+      });
+
+      if (self.iceGatheringState !== 'gathering') {
+        self.iceGatheringState = 'gathering';
+        self._emitGatheringStateChange();
+      }
+
+      // Emit candidate. Also emit null candidate when all gatherers are
+      // complete.
+      if (!end) {
+        self.dispatchEvent(event);
+        if (typeof self.onicecandidate === 'function') {
+          self.onicecandidate(event);
+        }
+      }
+      if (complete) {
+        self.dispatchEvent(new Event('icecandidate'));
+        if (typeof self.onicecandidate === 'function') {
+          self.onicecandidate(new Event('icecandidate'));
+        }
+        self.iceGatheringState = 'complete';
+        self._emitGatheringStateChange();
+      }
+    };
+
+    // emit already gathered candidates.
+    window.setTimeout(function() {
+      candidates.forEach(function(candidate) {
+        var e = new Event('RTCIceGatherEvent');
+        e.candidate = candidate;
+        iceGatherer.onlocalcandidate(e);
+      });
+    }, 0);
+  };
+
+  // Create ICE transport and DTLS transport.
+  RTCPeerConnection.prototype._createIceAndDtlsTransports = function() {
+    var self = this;
+    var iceTransport = new window.RTCIceTransport(null);
+    iceTransport.onicestatechange = function() {
+      self._updateConnectionState();
+    };
+
+    var dtlsTransport = new window.RTCDtlsTransport(iceTransport);
+    dtlsTransport.ondtlsstatechange = function() {
+      self._updateConnectionState();
+    };
+    dtlsTransport.onerror = function() {
+      // onerror does not set state to failed by itself.
+      Object.defineProperty(dtlsTransport, 'state',
+          {value: 'failed', writable: true});
+      self._updateConnectionState();
+    };
+
+    return {
+      iceTransport: iceTransport,
+      dtlsTransport: dtlsTransport
+    };
+  };
+
+  // Destroy ICE gatherer, ICE transport and DTLS transport.
+  // Without triggering the callbacks.
+  RTCPeerConnection.prototype._disposeIceAndDtlsTransports = function(
+      sdpMLineIndex) {
+    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
+    if (iceGatherer) {
+      delete iceGatherer.onlocalcandidate;
+      delete this.transceivers[sdpMLineIndex].iceGatherer;
+    }
+    var iceTransport = this.transceivers[sdpMLineIndex].iceTransport;
+    if (iceTransport) {
+      delete iceTransport.onicestatechange;
+      delete this.transceivers[sdpMLineIndex].iceTransport;
+    }
+    var dtlsTransport = this.transceivers[sdpMLineIndex].dtlsTransport;
+    if (dtlsTransport) {
+      delete dtlsTransport.ondtlsstatechange;
+      delete dtlsTransport.onerror;
+      delete this.transceivers[sdpMLineIndex].dtlsTransport;
+    }
+  };
+
+  // Start the RTP Sender and Receiver for a transceiver.
+  RTCPeerConnection.prototype._transceive = function(transceiver,
+      send, recv) {
+    var params = getCommonCapabilities(transceiver.localCapabilities,
+        transceiver.remoteCapabilities);
+    if (send && transceiver.rtpSender) {
+      params.encodings = transceiver.sendEncodingParameters;
+      params.rtcp = {
+        cname: SDPUtils.localCName,
+        compound: transceiver.rtcpParameters.compound
+      };
+      if (transceiver.recvEncodingParameters.length) {
+        params.rtcp.ssrc = transceiver.recvEncodingParameters[0].ssrc;
+      }
+      transceiver.rtpSender.send(params);
+    }
+    if (recv && transceiver.rtpReceiver && params.codecs.length > 0) {
+      // remove RTX field in Edge 14942
+      if (transceiver.kind === 'video'
+          && transceiver.recvEncodingParameters
+          && edgeVersion < 15019) {
+        transceiver.recvEncodingParameters.forEach(function(p) {
+          delete p.rtx;
+        });
+      }
+      params.encodings = transceiver.recvEncodingParameters;
+      params.rtcp = {
+        cname: transceiver.rtcpParameters.cname,
+        compound: transceiver.rtcpParameters.compound
+      };
+      if (transceiver.sendEncodingParameters.length) {
+        params.rtcp.ssrc = transceiver.sendEncodingParameters[0].ssrc;
+      }
+      transceiver.rtpReceiver.receive(params);
+    }
+  };
+
+  RTCPeerConnection.prototype.setLocalDescription = function(description) {
+    var self = this;
+    var args = arguments;
+
+    if (!isActionAllowedInSignalingState('setLocalDescription',
+        description.type, this.signalingState)) {
+      return new Promise(function(resolve, reject) {
+        var e = new Error('Can not set local ' + description.type +
+            ' in state ' + self.signalingState);
+        e.name = 'InvalidStateError';
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [e]);
+        }
+        reject(e);
+      });
+    }
+
+    var sections;
+    var sessionpart;
+    if (description.type === 'offer') {
+      // VERY limited support for SDP munging. Limited to:
+      // * changing the order of codecs
+      sections = SDPUtils.splitSections(description.sdp);
+      sessionpart = sections.shift();
+      sections.forEach(function(mediaSection, sdpMLineIndex) {
+        var caps = SDPUtils.parseRtpParameters(mediaSection);
+        self.transceivers[sdpMLineIndex].localCapabilities = caps;
+      });
+
+      this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+        self._gather(transceiver.mid, sdpMLineIndex);
+      });
+    } else if (description.type === 'answer') {
+      sections = SDPUtils.splitSections(self.remoteDescription.sdp);
+      sessionpart = sections.shift();
+      var isIceLite = SDPUtils.matchPrefix(sessionpart,
+          'a=ice-lite').length > 0;
+      sections.forEach(function(mediaSection, sdpMLineIndex) {
+        var transceiver = self.transceivers[sdpMLineIndex];
+        var iceGatherer = transceiver.iceGatherer;
+        var iceTransport = transceiver.iceTransport;
+        var dtlsTransport = transceiver.dtlsTransport;
+        var localCapabilities = transceiver.localCapabilities;
+        var remoteCapabilities = transceiver.remoteCapabilities;
+
+        // treat bundle-only as not-rejected.
+        var rejected = SDPUtils.isRejected(mediaSection) &&
+            !SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 1;
+
+        if (!rejected && !transceiver.isDatachannel) {
+          var remoteIceParameters = SDPUtils.getIceParameters(
+              mediaSection, sessionpart);
+          var remoteDtlsParameters = SDPUtils.getDtlsParameters(
+              mediaSection, sessionpart);
+          if (isIceLite) {
+            remoteDtlsParameters.role = 'server';
+          }
+
+          if (!self.usingBundle || sdpMLineIndex === 0) {
+            self._gather(transceiver.mid, sdpMLineIndex);
+            if (iceTransport.state === 'new') {
+              iceTransport.start(iceGatherer, remoteIceParameters,
+                  isIceLite ? 'controlling' : 'controlled');
+            }
+            if (dtlsTransport.state === 'new') {
+              dtlsTransport.start(remoteDtlsParameters);
+            }
+          }
+
+          // Calculate intersection of capabilities.
+          var params = getCommonCapabilities(localCapabilities,
+              remoteCapabilities);
+
+          // Start the RTCRtpSender. The RTCRtpReceiver for this
+          // transceiver has already been started in setRemoteDescription.
+          self._transceive(transceiver,
+              params.codecs.length > 0,
+              false);
+        }
+      });
+    }
+
+    this.localDescription = {
+      type: description.type,
+      sdp: description.sdp
+    };
+    switch (description.type) {
+      case 'offer':
+        this._updateSignalingState('have-local-offer');
+        break;
+      case 'answer':
+        this._updateSignalingState('stable');
+        break;
+      default:
+        throw new TypeError('unsupported type "' + description.type +
+            '"');
+    }
+
+    // If a success callback was provided, emit ICE candidates after it
+    // has been executed. Otherwise, emit callback after the Promise is
+    // resolved.
+    var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
+        arguments[1];
+    return new Promise(function(resolve) {
+      if (cb) {
+        cb.apply(null);
+      }
+      resolve();
+    });
+  };
+
+  RTCPeerConnection.prototype.setRemoteDescription = function(description) {
+    var self = this;
+    var args = arguments;
+
+    if (!isActionAllowedInSignalingState('setRemoteDescription',
+        description.type, this.signalingState)) {
+      return new Promise(function(resolve, reject) {
+        var e = new Error('Can not set remote ' + description.type +
+            ' in state ' + self.signalingState);
+        e.name = 'InvalidStateError';
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [e]);
+        }
+        reject(e);
+      });
+    }
+
+    var streams = {};
+    this.remoteStreams.forEach(function(stream) {
+      streams[stream.id] = stream;
+    });
+    var receiverList = [];
+    var sections = SDPUtils.splitSections(description.sdp);
+    var sessionpart = sections.shift();
+    var isIceLite = SDPUtils.matchPrefix(sessionpart,
+        'a=ice-lite').length > 0;
+    var usingBundle = SDPUtils.matchPrefix(sessionpart,
+        'a=group:BUNDLE ').length > 0;
+    this.usingBundle = usingBundle;
+    var iceOptions = SDPUtils.matchPrefix(sessionpart,
+        'a=ice-options:')[0];
+    if (iceOptions) {
+      this.canTrickleIceCandidates = iceOptions.substr(14).split(' ')
+          .indexOf('trickle') >= 0;
+    } else {
+      this.canTrickleIceCandidates = false;
+    }
+
+    sections.forEach(function(mediaSection, sdpMLineIndex) {
+      var lines = SDPUtils.splitLines(mediaSection);
+      var kind = SDPUtils.getKind(mediaSection);
+      // treat bundle-only as not-rejected.
+      var rejected = SDPUtils.isRejected(mediaSection) &&
+          !SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 1;
+      var protocol = lines[0].substr(2).split(' ')[2];
+
+      var direction = SDPUtils.getDirection(mediaSection, sessionpart);
+      var remoteMsid = SDPUtils.parseMsid(mediaSection);
+
+      var mid = SDPUtils.getMid(mediaSection) || SDPUtils.generateIdentifier();
+
+      // Reject datachannels which are not implemented yet.
+      if (kind === 'application' && protocol === 'DTLS/SCTP') {
+        self.transceivers[sdpMLineIndex] = {
+          mid: mid,
+          isDatachannel: true
+        };
+        return;
+      }
+
+      var transceiver;
+      var iceGatherer;
+      var iceTransport;
+      var dtlsTransport;
+      var rtpReceiver;
+      var sendEncodingParameters;
+      var recvEncodingParameters;
+      var localCapabilities;
+
+      var track;
+      // FIXME: ensure the mediaSection has rtcp-mux set.
+      var remoteCapabilities = SDPUtils.parseRtpParameters(mediaSection);
+      var remoteIceParameters;
+      var remoteDtlsParameters;
+      if (!rejected) {
+        remoteIceParameters = SDPUtils.getIceParameters(mediaSection,
+            sessionpart);
+        remoteDtlsParameters = SDPUtils.getDtlsParameters(mediaSection,
+            sessionpart);
+        remoteDtlsParameters.role = 'client';
+      }
+      recvEncodingParameters =
+          SDPUtils.parseRtpEncodingParameters(mediaSection);
+
+      var rtcpParameters = SDPUtils.parseRtcpParameters(mediaSection);
+
+      var isComplete = SDPUtils.matchPrefix(mediaSection,
+          'a=end-of-candidates', sessionpart).length > 0;
+      var cands = SDPUtils.matchPrefix(mediaSection, 'a=candidate:')
+          .map(function(cand) {
+            return SDPUtils.parseCandidate(cand);
+          })
+          .filter(function(cand) {
+            return cand.component === 1;
+          });
+
+      // Check if we can use BUNDLE and dispose transports.
+      if ((description.type === 'offer' || description.type === 'answer') &&
+          !rejected && usingBundle && sdpMLineIndex > 0 &&
+          self.transceivers[sdpMLineIndex]) {
+        self._disposeIceAndDtlsTransports(sdpMLineIndex);
+        self.transceivers[sdpMLineIndex].iceGatherer =
+            self.transceivers[0].iceGatherer;
+        self.transceivers[sdpMLineIndex].iceTransport =
+            self.transceivers[0].iceTransport;
+        self.transceivers[sdpMLineIndex].dtlsTransport =
+            self.transceivers[0].dtlsTransport;
+        if (self.transceivers[sdpMLineIndex].rtpSender) {
+          self.transceivers[sdpMLineIndex].rtpSender.setTransport(
+              self.transceivers[0].dtlsTransport);
+        }
+        if (self.transceivers[sdpMLineIndex].rtpReceiver) {
+          self.transceivers[sdpMLineIndex].rtpReceiver.setTransport(
+              self.transceivers[0].dtlsTransport);
+        }
+      }
+      if (description.type === 'offer' && !rejected) {
+        transceiver = self.transceivers[sdpMLineIndex] ||
+            self._createTransceiver(kind);
+        transceiver.mid = mid;
+
+        if (!transceiver.iceGatherer) {
+          transceiver.iceGatherer = self._createIceGatherer(sdpMLineIndex,
+              usingBundle);
+        }
+
+        if (cands.length && transceiver.iceTransport.state === 'new') {
+          if (isComplete && (!usingBundle || sdpMLineIndex === 0)) {
+            transceiver.iceTransport.setRemoteCandidates(cands);
+          } else {
+            cands.forEach(function(candidate) {
+              maybeAddCandidate(transceiver.iceTransport, candidate);
+            });
+          }
+        }
+
+        localCapabilities = window.RTCRtpReceiver.getCapabilities(kind);
+
+        // filter RTX until additional stuff needed for RTX is implemented
+        // in adapter.js
+        if (edgeVersion < 15019) {
+          localCapabilities.codecs = localCapabilities.codecs.filter(
+              function(codec) {
+                return codec.name !== 'rtx';
+              });
+        }
+
+        sendEncodingParameters = transceiver.sendEncodingParameters || [{
+          ssrc: (2 * sdpMLineIndex + 2) * 1001
+        }];
+
+        var isNewTrack = false;
+        if (direction === 'sendrecv' || direction === 'sendonly') {
+          isNewTrack = !transceiver.rtpReceiver;
+          rtpReceiver = transceiver.rtpReceiver ||
+              new window.RTCRtpReceiver(transceiver.dtlsTransport, kind);
+
+          if (isNewTrack) {
+            var stream;
+            track = rtpReceiver.track;
+            // FIXME: does not work with Plan B.
+            if (remoteMsid) {
+              if (!streams[remoteMsid.stream]) {
+                streams[remoteMsid.stream] = new window.MediaStream();
+                Object.defineProperty(streams[remoteMsid.stream], 'id', {
+                  get: function() {
+                    return remoteMsid.stream;
+                  }
+                });
+              }
+              Object.defineProperty(track, 'id', {
+                get: function() {
+                  return remoteMsid.track;
+                }
+              });
+              stream = streams[remoteMsid.stream];
+            } else {
+              if (!streams.default) {
+                streams.default = new window.MediaStream();
+              }
+              stream = streams.default;
+            }
+            stream.addTrack(track);
+            receiverList.push([track, rtpReceiver, stream]);
+          }
+        }
+
+        transceiver.localCapabilities = localCapabilities;
+        transceiver.remoteCapabilities = remoteCapabilities;
+        transceiver.rtpReceiver = rtpReceiver;
+        transceiver.rtcpParameters = rtcpParameters;
+        transceiver.sendEncodingParameters = sendEncodingParameters;
+        transceiver.recvEncodingParameters = recvEncodingParameters;
+
+        // Start the RTCRtpReceiver now. The RTPSender is started in
+        // setLocalDescription.
+        self._transceive(self.transceivers[sdpMLineIndex],
+            false,
+            isNewTrack);
+      } else if (description.type === 'answer' && !rejected) {
+        transceiver = self.transceivers[sdpMLineIndex];
+        iceGatherer = transceiver.iceGatherer;
+        iceTransport = transceiver.iceTransport;
+        dtlsTransport = transceiver.dtlsTransport;
+        rtpReceiver = transceiver.rtpReceiver;
+        sendEncodingParameters = transceiver.sendEncodingParameters;
+        localCapabilities = transceiver.localCapabilities;
+
+        self.transceivers[sdpMLineIndex].recvEncodingParameters =
+            recvEncodingParameters;
+        self.transceivers[sdpMLineIndex].remoteCapabilities =
+            remoteCapabilities;
+        self.transceivers[sdpMLineIndex].rtcpParameters = rtcpParameters;
+
+        if (cands.length && iceTransport.state === 'new') {
+          if ((isIceLite || isComplete) &&
+              (!usingBundle || sdpMLineIndex === 0)) {
+            iceTransport.setRemoteCandidates(cands);
+          } else {
+            cands.forEach(function(candidate) {
+              maybeAddCandidate(transceiver.iceTransport, candidate);
+            });
+          }
+        }
+
+        if (!usingBundle || sdpMLineIndex === 0) {
+          if (iceTransport.state === 'new') {
+            iceTransport.start(iceGatherer, remoteIceParameters,
+                'controlling');
+          }
+          if (dtlsTransport.state === 'new') {
+            dtlsTransport.start(remoteDtlsParameters);
+          }
+        }
+
+        self._transceive(transceiver,
+            direction === 'sendrecv' || direction === 'recvonly',
+            direction === 'sendrecv' || direction === 'sendonly');
+
+        if (rtpReceiver &&
+            (direction === 'sendrecv' || direction === 'sendonly')) {
+          track = rtpReceiver.track;
+          if (remoteMsid) {
+            if (!streams[remoteMsid.stream]) {
+              streams[remoteMsid.stream] = new window.MediaStream();
+            }
+            streams[remoteMsid.stream].addTrack(track);
+            receiverList.push([track, rtpReceiver, streams[remoteMsid.stream]]);
+          } else {
+            if (!streams.default) {
+              streams.default = new window.MediaStream();
+            }
+            streams.default.addTrack(track);
+            receiverList.push([track, rtpReceiver, streams.default]);
+          }
+        } else {
+          // FIXME: actually the receiver should be created later.
+          delete transceiver.rtpReceiver;
+        }
+      }
+    });
+
+    if (this._dtlsRole === undefined) {
+      this._dtlsRole = description.type === 'offer' ? 'active' : 'passive';
+    }
+
+    this.remoteDescription = {
+      type: description.type,
+      sdp: description.sdp
+    };
+    switch (description.type) {
+      case 'offer':
+        this._updateSignalingState('have-remote-offer');
+        break;
+      case 'answer':
+        this._updateSignalingState('stable');
+        break;
+      default:
+        throw new TypeError('unsupported type "' + description.type +
+            '"');
+    }
+    Object.keys(streams).forEach(function(sid) {
+      var stream = streams[sid];
+      if (stream.getTracks().length) {
+        if (self.remoteStreams.indexOf(stream) === -1) {
+          self.remoteStreams.push(stream);
+          var event = new Event('addstream');
+          event.stream = stream;
+          window.setTimeout(function() {
+            self.dispatchEvent(event);
+            if (typeof self.onaddstream === 'function') {
+              self.onaddstream(event);
+            }
+          });
+        }
+
+        receiverList.forEach(function(item) {
+          var track = item[0];
+          var receiver = item[1];
+          if (stream.id !== item[2].id) {
+            return;
+          }
+          var trackEvent = new Event('track');
+          trackEvent.track = track;
+          trackEvent.receiver = receiver;
+          trackEvent.transceiver = {receiver: receiver};
+          trackEvent.streams = [stream];
+          window.setTimeout(function() {
+            self.dispatchEvent(trackEvent);
+            if (typeof self.ontrack === 'function') {
+              self.ontrack(trackEvent);
+            }
+          });
+        });
+      }
+    });
+
+    // check whether addIceCandidate({}) was called within four seconds after
+    // setRemoteDescription.
+    window.setTimeout(function() {
+      if (!(self && self.transceivers)) {
+        return;
+      }
+      self.transceivers.forEach(function(transceiver) {
+        if (transceiver.iceTransport &&
+            transceiver.iceTransport.state === 'new' &&
+            transceiver.iceTransport.getRemoteCandidates().length > 0) {
+          console.warn('Timeout for addRemoteCandidate. Consider sending ' +
+              'an end-of-candidates notification');
+          transceiver.iceTransport.addRemoteCandidate({});
+        }
+      });
+    }, 4000);
+
+    return new Promise(function(resolve) {
+      if (args.length > 1 && typeof args[1] === 'function') {
+        args[1].apply(null);
+      }
+      resolve();
+    });
+  };
+
+  RTCPeerConnection.prototype.close = function() {
+    this.transceivers.forEach(function(transceiver) {
+      /* not yet
+      if (transceiver.iceGatherer) {
+        transceiver.iceGatherer.close();
+      }
+      */
+      if (transceiver.iceTransport) {
+        transceiver.iceTransport.stop();
+      }
+      if (transceiver.dtlsTransport) {
+        transceiver.dtlsTransport.stop();
+      }
+      if (transceiver.rtpSender) {
+        transceiver.rtpSender.stop();
+      }
+      if (transceiver.rtpReceiver) {
+        transceiver.rtpReceiver.stop();
+      }
+    });
+    // FIXME: clean up tracks, local streams, remote streams, etc
+    this._updateSignalingState('closed');
+  };
+
+  // Update the signaling state.
+  RTCPeerConnection.prototype._updateSignalingState = function(newState) {
+    this.signalingState = newState;
+    var event = new Event('signalingstatechange');
+    this.dispatchEvent(event);
+    if (typeof this.onsignalingstatechange === 'function') {
+      this.onsignalingstatechange(event);
+    }
+  };
+
+  // Determine whether to fire the negotiationneeded event.
+  RTCPeerConnection.prototype._maybeFireNegotiationNeeded = function() {
+    var self = this;
+    if (this.signalingState !== 'stable' || this.needNegotiation === true) {
+      return;
+    }
+    this.needNegotiation = true;
+    window.setTimeout(function() {
+      if (self.needNegotiation === false) {
+        return;
+      }
+      self.needNegotiation = false;
+      var event = new Event('negotiationneeded');
+      self.dispatchEvent(event);
+      if (typeof self.onnegotiationneeded === 'function') {
+        self.onnegotiationneeded(event);
+      }
+    }, 0);
+  };
+
+  // Update the connection state.
+  RTCPeerConnection.prototype._updateConnectionState = function() {
+    var newState;
+    var states = {
+      'new': 0,
+      closed: 0,
+      connecting: 0,
+      checking: 0,
+      connected: 0,
+      completed: 0,
+      disconnected: 0,
+      failed: 0
+    };
+    this.transceivers.forEach(function(transceiver) {
+      states[transceiver.iceTransport.state]++;
+      states[transceiver.dtlsTransport.state]++;
+    });
+    // ICETransport.completed and connected are the same for this purpose.
+    states.connected += states.completed;
+
+    newState = 'new';
+    if (states.failed > 0) {
+      newState = 'failed';
+    } else if (states.connecting > 0 || states.checking > 0) {
+      newState = 'connecting';
+    } else if (states.disconnected > 0) {
+      newState = 'disconnected';
+    } else if (states.new > 0) {
+      newState = 'new';
+    } else if (states.connected > 0 || states.completed > 0) {
+      newState = 'connected';
+    }
+
+    if (newState !== this.iceConnectionState) {
+      this.iceConnectionState = newState;
+      var event = new Event('iceconnectionstatechange');
+      this.dispatchEvent(event);
+      if (typeof this.oniceconnectionstatechange === 'function') {
+        this.oniceconnectionstatechange(event);
+      }
+    }
+  };
+
+  RTCPeerConnection.prototype.createOffer = function() {
+    var self = this;
+    var args = arguments;
+
+    var offerOptions;
+    if (arguments.length === 1 && typeof arguments[0] !== 'function') {
+      offerOptions = arguments[0];
+    } else if (arguments.length === 3) {
+      offerOptions = arguments[2];
+    }
+
+    var numAudioTracks = this.transceivers.filter(function(t) {
+      return t.kind === 'audio';
+    }).length;
+    var numVideoTracks = this.transceivers.filter(function(t) {
+      return t.kind === 'video';
+    }).length;
+
+    // Determine number of audio and video tracks we need to send/recv.
+    if (offerOptions) {
+      // Reject Chrome legacy constraints.
+      if (offerOptions.mandatory || offerOptions.optional) {
+        throw new TypeError(
+            'Legacy mandatory/optional constraints not supported.');
+      }
+      if (offerOptions.offerToReceiveAudio !== undefined) {
+        if (offerOptions.offerToReceiveAudio === true) {
+          numAudioTracks = 1;
+        } else if (offerOptions.offerToReceiveAudio === false) {
+          numAudioTracks = 0;
+        } else {
+          numAudioTracks = offerOptions.offerToReceiveAudio;
+        }
+      }
+      if (offerOptions.offerToReceiveVideo !== undefined) {
+        if (offerOptions.offerToReceiveVideo === true) {
+          numVideoTracks = 1;
+        } else if (offerOptions.offerToReceiveVideo === false) {
+          numVideoTracks = 0;
+        } else {
+          numVideoTracks = offerOptions.offerToReceiveVideo;
+        }
+      }
+    }
+
+    this.transceivers.forEach(function(transceiver) {
+      if (transceiver.kind === 'audio') {
+        numAudioTracks--;
+        if (numAudioTracks < 0) {
+          transceiver.wantReceive = false;
+        }
+      } else if (transceiver.kind === 'video') {
+        numVideoTracks--;
+        if (numVideoTracks < 0) {
+          transceiver.wantReceive = false;
+        }
+      }
+    });
+
+    // Create M-lines for recvonly streams.
+    while (numAudioTracks > 0 || numVideoTracks > 0) {
+      if (numAudioTracks > 0) {
+        this._createTransceiver('audio');
+        numAudioTracks--;
+      }
+      if (numVideoTracks > 0) {
+        this._createTransceiver('video');
+        numVideoTracks--;
+      }
+    }
+
+    var sdp = SDPUtils.writeSessionBoilerplate(this._sdpSessionId,
+        this._sdpSessionVersion++);
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      // For each track, create an ice gatherer, ice transport,
+      // dtls transport, potentially rtpsender and rtpreceiver.
+      var track = transceiver.track;
+      var kind = transceiver.kind;
+      var mid = SDPUtils.generateIdentifier();
+      transceiver.mid = mid;
+
+      if (!transceiver.iceGatherer) {
+        transceiver.iceGatherer = self._createIceGatherer(sdpMLineIndex,
+            self.usingBundle);
+      }
+
+      var localCapabilities = window.RTCRtpSender.getCapabilities(kind);
+      // filter RTX until additional stuff needed for RTX is implemented
+      // in adapter.js
+      if (edgeVersion < 15019) {
+        localCapabilities.codecs = localCapabilities.codecs.filter(
+            function(codec) {
+              return codec.name !== 'rtx';
+            });
+      }
+      localCapabilities.codecs.forEach(function(codec) {
+        // work around https://bugs.chromium.org/p/webrtc/issues/detail?id=6552
+        // by adding level-asymmetry-allowed=1
+        if (codec.name === 'H264' &&
+            codec.parameters['level-asymmetry-allowed'] === undefined) {
+          codec.parameters['level-asymmetry-allowed'] = '1';
+        }
+      });
+
+      // generate an ssrc now, to be used later in rtpSender.send
+      var sendEncodingParameters = transceiver.sendEncodingParameters || [{
+        ssrc: (2 * sdpMLineIndex + 1) * 1001
+      }];
+      if (track) {
+        // add RTX
+        if (edgeVersion >= 15019 && kind === 'video' &&
+            !sendEncodingParameters[0].rtx) {
+          sendEncodingParameters[0].rtx = {
+            ssrc: sendEncodingParameters[0].ssrc + 1
+          };
+        }
+      }
+
+      if (transceiver.wantReceive) {
+        transceiver.rtpReceiver = new window.RTCRtpReceiver(
+            transceiver.dtlsTransport, kind);
+      }
+
+      transceiver.localCapabilities = localCapabilities;
+      transceiver.sendEncodingParameters = sendEncodingParameters;
+    });
+
+    // always offer BUNDLE and dispose on return if not supported.
+    if (this._config.bundlePolicy !== 'max-compat') {
+      sdp += 'a=group:BUNDLE ' + this.transceivers.map(function(t) {
+        return t.mid;
+      }).join(' ') + '\r\n';
+    }
+    sdp += 'a=ice-options:trickle\r\n';
+
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      sdp += writeMediaSection(transceiver, transceiver.localCapabilities,
+          'offer', transceiver.stream, self._dtlsRole);
+      sdp += 'a=rtcp-rsize\r\n';
+
+      if (transceiver.iceGatherer && self.iceGatheringState !== 'new' &&
+          (sdpMLineIndex === 0 || !self.usingBundle)) {
+        transceiver.iceGatherer.getLocalCandidates().forEach(function(cand) {
+          cand.component = 1;
+          sdp += 'a=' + SDPUtils.writeCandidate(cand) + '\r\n';
+        });
+
+        if (transceiver.iceGatherer.state === 'completed') {
+          sdp += 'a=end-of-candidates\r\n';
+        }
+      }
+    });
+
+    var desc = new window.RTCSessionDescription({
+      type: 'offer',
+      sdp: sdp
+    });
+    return new Promise(function(resolve) {
+      if (args.length > 0 && typeof args[0] === 'function') {
+        args[0].apply(null, [desc]);
+        resolve();
+        return;
+      }
+      resolve(desc);
+    });
+  };
+
+  RTCPeerConnection.prototype.createAnswer = function() {
+    var self = this;
+    var args = arguments;
+
+    var sdp = SDPUtils.writeSessionBoilerplate(this._sdpSessionId,
+        this._sdpSessionVersion++);
+    if (this.usingBundle) {
+      sdp += 'a=group:BUNDLE ' + this.transceivers.map(function(t) {
+        return t.mid;
+      }).join(' ') + '\r\n';
+    }
+    var mediaSectionsInOffer = SDPUtils.splitSections(
+        this.remoteDescription.sdp).length - 1;
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      if (sdpMLineIndex + 1 > mediaSectionsInOffer) {
+        return;
+      }
+      if (transceiver.isDatachannel) {
+        sdp += 'm=application 0 DTLS/SCTP 5000\r\n' +
+            'c=IN IP4 0.0.0.0\r\n' +
+            'a=mid:' + transceiver.mid + '\r\n';
+        return;
+      }
+
+      // FIXME: look at direction.
+      if (transceiver.stream) {
+        var localTrack;
+        if (transceiver.kind === 'audio') {
+          localTrack = transceiver.stream.getAudioTracks()[0];
+        } else if (transceiver.kind === 'video') {
+          localTrack = transceiver.stream.getVideoTracks()[0];
+        }
+        if (localTrack) {
+          // add RTX
+          if (edgeVersion >= 15019 && transceiver.kind === 'video' &&
+              !transceiver.sendEncodingParameters[0].rtx) {
+            transceiver.sendEncodingParameters[0].rtx = {
+              ssrc: transceiver.sendEncodingParameters[0].ssrc + 1
+            };
+          }
+        }
+      }
+
+      // Calculate intersection of capabilities.
+      var commonCapabilities = getCommonCapabilities(
+          transceiver.localCapabilities,
+          transceiver.remoteCapabilities);
+
+      var hasRtx = commonCapabilities.codecs.filter(function(c) {
+        return c.name.toLowerCase() === 'rtx';
+      }).length;
+      if (!hasRtx && transceiver.sendEncodingParameters[0].rtx) {
+        delete transceiver.sendEncodingParameters[0].rtx;
+      }
+
+      sdp += writeMediaSection(transceiver, commonCapabilities,
+          'answer', transceiver.stream, self._dtlsRole);
+      if (transceiver.rtcpParameters &&
+          transceiver.rtcpParameters.reducedSize) {
+        sdp += 'a=rtcp-rsize\r\n';
+      }
+    });
+
+    var desc = new window.RTCSessionDescription({
+      type: 'answer',
+      sdp: sdp
+    });
+    return new Promise(function(resolve) {
+      if (args.length > 0 && typeof args[0] === 'function') {
+        args[0].apply(null, [desc]);
+        resolve();
+        return;
+      }
+      resolve(desc);
+    });
+  };
+
+  RTCPeerConnection.prototype.addIceCandidate = function(candidate) {
+    var err;
+    var sections;
+    if (!candidate || candidate.candidate === '') {
+      for (var j = 0; j < this.transceivers.length; j++) {
+        if (this.transceivers[j].isDatachannel) {
+          continue;
+        }
+        this.transceivers[j].iceTransport.addRemoteCandidate({});
+        sections = SDPUtils.splitSections(this.remoteDescription.sdp);
+        sections[j + 1] += 'a=end-of-candidates\r\n';
+        this.remoteDescription.sdp = sections.join('');
+        if (this.usingBundle) {
+          break;
+        }
+      }
+    } else if (!(candidate.sdpMLineIndex !== undefined || candidate.sdpMid)) {
+      throw new TypeError('sdpMLineIndex or sdpMid required');
+    } else if (!this.remoteDescription) {
+      err = new Error('Can not add ICE candidate without ' +
+          'a remote description');
+      err.name = 'InvalidStateError';
+    } else {
+      var sdpMLineIndex = candidate.sdpMLineIndex;
+      if (candidate.sdpMid) {
+        for (var i = 0; i < this.transceivers.length; i++) {
+          if (this.transceivers[i].mid === candidate.sdpMid) {
+            sdpMLineIndex = i;
+            break;
+          }
+        }
+      }
+      var transceiver = this.transceivers[sdpMLineIndex];
+      if (transceiver) {
+        if (transceiver.isDatachannel) {
+          return Promise.resolve();
+        }
+        var cand = Object.keys(candidate.candidate).length > 0 ?
+            SDPUtils.parseCandidate(candidate.candidate) : {};
+        // Ignore Chrome's invalid candidates since Edge does not like them.
+        if (cand.protocol === 'tcp' && (cand.port === 0 || cand.port === 9)) {
+          return Promise.resolve();
+        }
+        // Ignore RTCP candidates, we assume RTCP-MUX.
+        if (cand.component && cand.component !== 1) {
+          return Promise.resolve();
+        }
+        // when using bundle, avoid adding candidates to the wrong
+        // ice transport. And avoid adding candidates added in the SDP.
+        if (sdpMLineIndex === 0 || (sdpMLineIndex > 0 &&
+            transceiver.iceTransport !== this.transceivers[0].iceTransport)) {
+          if (!maybeAddCandidate(transceiver.iceTransport, cand)) {
+            err = new Error('Can not add ICE candidate');
+            err.name = 'OperationError';
+          }
+        }
+
+        if (!err) {
+          // update the remoteDescription.
+          var candidateString = candidate.candidate.trim();
+          if (candidateString.indexOf('a=') === 0) {
+            candidateString = candidateString.substr(2);
+          }
+          sections = SDPUtils.splitSections(this.remoteDescription.sdp);
+          sections[sdpMLineIndex + 1] += 'a=' +
+              (cand.type ? candidateString : 'end-of-candidates')
+              + '\r\n';
+          this.remoteDescription.sdp = sections.join('');
+        }
+      } else {
+        err = new Error('Can not add ICE candidate');
+        err.name = 'OperationError';
+      }
+    }
+    var args = arguments;
+    return new Promise(function(resolve, reject) {
+      if (err) {
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [err]);
+        }
+        reject(err);
+      } else {
+        if (args.length > 1 && typeof args[1] === 'function') {
+          args[1].apply(null);
+        }
+        resolve();
+      }
+    });
+  };
+
+  RTCPeerConnection.prototype.getStats = function() {
+    var promises = [];
+    this.transceivers.forEach(function(transceiver) {
+      ['rtpSender', 'rtpReceiver', 'iceGatherer', 'iceTransport',
+          'dtlsTransport'].forEach(function(method) {
+            if (transceiver[method]) {
+              promises.push(transceiver[method].getStats());
+            }
+          });
+    });
+    var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
+        arguments[1];
+    var fixStatsType = function(stat) {
+      return {
+        inboundrtp: 'inbound-rtp',
+        outboundrtp: 'outbound-rtp',
+        candidatepair: 'candidate-pair',
+        localcandidate: 'local-candidate',
+        remotecandidate: 'remote-candidate'
+      }[stat.type] || stat.type;
+    };
+    return new Promise(function(resolve) {
+      // shim getStats with maplike support
+      var results = new Map();
+      Promise.all(promises).then(function(res) {
+        res.forEach(function(result) {
+          Object.keys(result).forEach(function(id) {
+            result[id].type = fixStatsType(result[id]);
+            results.set(id, result[id]);
+          });
+        });
+        if (cb) {
+          cb.apply(null, results);
+        }
+        resolve(results);
+      });
+    });
+  };
+  return RTCPeerConnection;
+};
+
+},{"sdp":2}],2:[function(require,module,exports){
+ /* eslint-env node */
+'use strict';
+
+// SDP helpers.
+var SDPUtils = {};
+
+// Generate an alphanumeric identifier for cname or mids.
+// TODO: use UUIDs instead? https://gist.github.com/jed/982883
+SDPUtils.generateIdentifier = function() {
+  return Math.random().toString(36).substr(2, 10);
+};
+
+// The RTCP CNAME used by all peerconnections from the same JS.
+SDPUtils.localCName = SDPUtils.generateIdentifier();
+
+// Splits SDP into lines, dealing with both CRLF and LF.
+SDPUtils.splitLines = function(blob) {
+  return blob.trim().split('\n').map(function(line) {
+    return line.trim();
+  });
+};
+// Splits SDP into sessionpart and mediasections. Ensures CRLF.
+SDPUtils.splitSections = function(blob) {
+  var parts = blob.split('\nm=');
+  return parts.map(function(part, index) {
+    return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
+  });
+};
+
+// Returns lines that start with a certain prefix.
+SDPUtils.matchPrefix = function(blob, prefix) {
+  return SDPUtils.splitLines(blob).filter(function(line) {
+    return line.indexOf(prefix) === 0;
+  });
+};
+
+// Parses an ICE candidate line. Sample input:
+// candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8
+// rport 55996"
+SDPUtils.parseCandidate = function(line) {
+  var parts;
+  // Parse both variants.
+  if (line.indexOf('a=candidate:') === 0) {
+    parts = line.substring(12).split(' ');
+  } else {
+    parts = line.substring(10).split(' ');
+  }
+
+  var candidate = {
+    foundation: parts[0],
+    component: parseInt(parts[1], 10),
+    protocol: parts[2].toLowerCase(),
+    priority: parseInt(parts[3], 10),
+    ip: parts[4],
+    port: parseInt(parts[5], 10),
+    // skip parts[6] == 'typ'
+    type: parts[7]
+  };
+
+  for (var i = 8; i < parts.length; i += 2) {
+    switch (parts[i]) {
+      case 'raddr':
+        candidate.relatedAddress = parts[i + 1];
+        break;
+      case 'rport':
+        candidate.relatedPort = parseInt(parts[i + 1], 10);
+        break;
+      case 'tcptype':
+        candidate.tcpType = parts[i + 1];
+        break;
+      case 'ufrag':
+        candidate.ufrag = parts[i + 1]; // for backward compability.
+        candidate.usernameFragment = parts[i + 1];
+        break;
+      default: // extension handling, in particular ufrag
+        candidate[parts[i]] = parts[i + 1];
+        break;
+    }
+  }
+  return candidate;
+};
+
+// Translates a candidate object into SDP candidate attribute.
+SDPUtils.writeCandidate = function(candidate) {
+  var sdp = [];
+  sdp.push(candidate.foundation);
+  sdp.push(candidate.component);
+  sdp.push(candidate.protocol.toUpperCase());
+  sdp.push(candidate.priority);
+  sdp.push(candidate.ip);
+  sdp.push(candidate.port);
+
+  var type = candidate.type;
+  sdp.push('typ');
+  sdp.push(type);
+  if (type !== 'host' && candidate.relatedAddress &&
+      candidate.relatedPort) {
+    sdp.push('raddr');
+    sdp.push(candidate.relatedAddress); // was: relAddr
+    sdp.push('rport');
+    sdp.push(candidate.relatedPort); // was: relPort
+  }
+  if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
+    sdp.push('tcptype');
+    sdp.push(candidate.tcpType);
+  }
+  if (candidate.ufrag) {
+    sdp.push('ufrag');
+    sdp.push(candidate.ufrag);
+  }
+  return 'candidate:' + sdp.join(' ');
+};
+
+// Parses an ice-options line, returns an array of option tags.
+// a=ice-options:foo bar
+SDPUtils.parseIceOptions = function(line) {
+  return line.substr(14).split(' ');
+}
+
+// Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
+// a=rtpmap:111 opus/48000/2
+SDPUtils.parseRtpMap = function(line) {
+  var parts = line.substr(9).split(' ');
+  var parsed = {
+    payloadType: parseInt(parts.shift(), 10) // was: id
+  };
+
+  parts = parts[0].split('/');
+
+  parsed.name = parts[0];
+  parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
+  // was: channels
+  parsed.numChannels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
+  return parsed;
+};
+
+// Generate an a=rtpmap line from RTCRtpCodecCapability or
+// RTCRtpCodecParameters.
+SDPUtils.writeRtpMap = function(codec) {
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
+      (codec.numChannels !== 1 ? '/' + codec.numChannels : '') + '\r\n';
+};
+
+// Parses an a=extmap line (headerextension from RFC 5285). Sample input:
+// a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
+// a=extmap:2/sendonly urn:ietf:params:rtp-hdrext:toffset
+SDPUtils.parseExtmap = function(line) {
+  var parts = line.substr(9).split(' ');
+  return {
+    id: parseInt(parts[0], 10),
+    direction: parts[0].indexOf('/') > 0 ? parts[0].split('/')[1] : 'sendrecv',
+    uri: parts[1]
+  };
+};
+
+// Generates a=extmap line from RTCRtpHeaderExtensionParameters or
+// RTCRtpHeaderExtension.
+SDPUtils.writeExtmap = function(headerExtension) {
+  return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
+      (headerExtension.direction && headerExtension.direction !== 'sendrecv'
+          ? '/' + headerExtension.direction
+          : '') +
+      ' ' + headerExtension.uri + '\r\n';
+};
+
+// Parses an ftmp line, returns dictionary. Sample input:
+// a=fmtp:96 vbr=on;cng=on
+// Also deals with vbr=on; cng=on
+SDPUtils.parseFmtp = function(line) {
+  var parsed = {};
+  var kv;
+  var parts = line.substr(line.indexOf(' ') + 1).split(';');
+  for (var j = 0; j < parts.length; j++) {
+    kv = parts[j].trim().split('=');
+    parsed[kv[0].trim()] = kv[1];
+  }
+  return parsed;
+};
+
+// Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeFmtp = function(codec) {
+  var line = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.parameters && Object.keys(codec.parameters).length) {
+    var params = [];
+    Object.keys(codec.parameters).forEach(function(param) {
+      params.push(param + '=' + codec.parameters[param]);
+    });
+    line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
+  }
+  return line;
+};
+
+// Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
+// a=rtcp-fb:98 nack rpsi
+SDPUtils.parseRtcpFb = function(line) {
+  var parts = line.substr(line.indexOf(' ') + 1).split(' ');
+  return {
+    type: parts.shift(),
+    parameter: parts.join(' ')
+  };
+};
+// Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeRtcpFb = function(codec) {
+  var lines = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
+    // FIXME: special handling for trr-int?
+    codec.rtcpFeedback.forEach(function(fb) {
+      lines += 'a=rtcp-fb:' + pt + ' ' + fb.type +
+      (fb.parameter && fb.parameter.length ? ' ' + fb.parameter : '') +
+          '\r\n';
+    });
+  }
+  return lines;
+};
+
+// Parses an RFC 5576 ssrc media attribute. Sample input:
+// a=ssrc:3735928559 cname:something
+SDPUtils.parseSsrcMedia = function(line) {
+  var sp = line.indexOf(' ');
+  var parts = {
+    ssrc: parseInt(line.substr(7, sp - 7), 10)
+  };
+  var colon = line.indexOf(':', sp);
+  if (colon > -1) {
+    parts.attribute = line.substr(sp + 1, colon - sp - 1);
+    parts.value = line.substr(colon + 1);
+  } else {
+    parts.attribute = line.substr(sp + 1);
+  }
+  return parts;
+};
+
+// Extracts the MID (RFC 5888) from a media section.
+// returns the MID or undefined if no mid line was found.
+SDPUtils.getMid = function(mediaSection) {
+  var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0];
+  if (mid) {
+    return mid.substr(6);
+  }
+}
+
+SDPUtils.parseFingerprint = function(line) {
+  var parts = line.substr(14).split(' ');
+  return {
+    algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
+    value: parts[1]
+  };
+};
+
+// Extracts DTLS parameters from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the fingerprint line as input. See also getIceParameters.
+SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.matchPrefix(mediaSection + sessionpart,
+      'a=fingerprint:');
+  // Note: a=setup line is ignored since we use the 'auto' role.
+  // Note2: 'algorithm' is not case sensitive except in Edge.
+  return {
+    role: 'auto',
+    fingerprints: lines.map(SDPUtils.parseFingerprint)
+  };
+};
+
+// Serializes DTLS parameters to SDP.
+SDPUtils.writeDtlsParameters = function(params, setupType) {
+  var sdp = 'a=setup:' + setupType + '\r\n';
+  params.fingerprints.forEach(function(fp) {
+    sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
+  });
+  return sdp;
+};
+// Parses ICE information from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the ice-ufrag and ice-pwd lines as input.
+SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  // Search in session part, too.
+  lines = lines.concat(SDPUtils.splitLines(sessionpart));
+  var iceParameters = {
+    usernameFragment: lines.filter(function(line) {
+      return line.indexOf('a=ice-ufrag:') === 0;
+    })[0].substr(12),
+    password: lines.filter(function(line) {
+      return line.indexOf('a=ice-pwd:') === 0;
+    })[0].substr(10)
+  };
+  return iceParameters;
+};
+
+// Serializes ICE parameters to SDP.
+SDPUtils.writeIceParameters = function(params) {
+  return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
+      'a=ice-pwd:' + params.password + '\r\n';
+};
+
+// Parses the SDP media section and returns RTCRtpParameters.
+SDPUtils.parseRtpParameters = function(mediaSection) {
+  var description = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: [],
+    rtcp: []
+  };
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
+    var pt = mline[i];
+    var rtpmapline = SDPUtils.matchPrefix(
+        mediaSection, 'a=rtpmap:' + pt + ' ')[0];
+    if (rtpmapline) {
+      var codec = SDPUtils.parseRtpMap(rtpmapline);
+      var fmtps = SDPUtils.matchPrefix(
+          mediaSection, 'a=fmtp:' + pt + ' ');
+      // Only the first a=fmtp:<pt> is considered.
+      codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
+      codec.rtcpFeedback = SDPUtils.matchPrefix(
+          mediaSection, 'a=rtcp-fb:' + pt + ' ')
+        .map(SDPUtils.parseRtcpFb);
+      description.codecs.push(codec);
+      // parse FEC mechanisms from rtpmap lines.
+      switch (codec.name.toUpperCase()) {
+        case 'RED':
+        case 'ULPFEC':
+          description.fecMechanisms.push(codec.name.toUpperCase());
+          break;
+        default: // only RED and ULPFEC are recognized as FEC mechanisms.
+          break;
+      }
+    }
+  }
+  SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
+    description.headerExtensions.push(SDPUtils.parseExtmap(line));
+  });
+  // FIXME: parse rtcp.
+  return description;
+};
+
+// Generates parts of the SDP media section describing the capabilities /
+// parameters.
+SDPUtils.writeRtpDescription = function(kind, caps) {
+  var sdp = '';
+
+  // Build the mline.
+  sdp += 'm=' + kind + ' ';
+  sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
+  sdp += ' UDP/TLS/RTP/SAVPF ';
+  sdp += caps.codecs.map(function(codec) {
+    if (codec.preferredPayloadType !== undefined) {
+      return codec.preferredPayloadType;
+    }
+    return codec.payloadType;
+  }).join(' ') + '\r\n';
+
+  sdp += 'c=IN IP4 0.0.0.0\r\n';
+  sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';
+
+  // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
+  caps.codecs.forEach(function(codec) {
+    sdp += SDPUtils.writeRtpMap(codec);
+    sdp += SDPUtils.writeFmtp(codec);
+    sdp += SDPUtils.writeRtcpFb(codec);
+  });
+  var maxptime = 0;
+  caps.codecs.forEach(function(codec) {
+    if (codec.maxptime > maxptime) {
+      maxptime = codec.maxptime;
+    }
+  });
+  if (maxptime > 0) {
+    sdp += 'a=maxptime:' + maxptime + '\r\n';
+  }
+  sdp += 'a=rtcp-mux\r\n';
+
+  caps.headerExtensions.forEach(function(extension) {
+    sdp += SDPUtils.writeExtmap(extension);
+  });
+  // FIXME: write fecMechanisms.
+  return sdp;
+};
+
+// Parses the SDP media section and returns an array of
+// RTCRtpEncodingParameters.
+SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
+  var encodingParameters = [];
+  var description = SDPUtils.parseRtpParameters(mediaSection);
+  var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
+  var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;
+
+  // filter a=ssrc:... cname:, ignore PlanB-msid
+  var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'cname';
+  });
+  var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
+  var secondarySsrc;
+
+  var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
+  .map(function(line) {
+    var parts = line.split(' ');
+    parts.shift();
+    return parts.map(function(part) {
+      return parseInt(part, 10);
+    });
+  });
+  if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
+    secondarySsrc = flows[0][1];
+  }
+
+  description.codecs.forEach(function(codec) {
+    if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
+      var encParam = {
+        ssrc: primarySsrc,
+        codecPayloadType: parseInt(codec.parameters.apt, 10),
+        rtx: {
+          ssrc: secondarySsrc
+        }
+      };
+      encodingParameters.push(encParam);
+      if (hasRed) {
+        encParam = JSON.parse(JSON.stringify(encParam));
+        encParam.fec = {
+          ssrc: secondarySsrc,
+          mechanism: hasUlpfec ? 'red+ulpfec' : 'red'
+        };
+        encodingParameters.push(encParam);
+      }
+    }
+  });
+  if (encodingParameters.length === 0 && primarySsrc) {
+    encodingParameters.push({
+      ssrc: primarySsrc
+    });
+  }
+
+  // we support both b=AS and b=TIAS but interpret AS as TIAS.
+  var bandwidth = SDPUtils.matchPrefix(mediaSection, 'b=');
+  if (bandwidth.length) {
+    if (bandwidth[0].indexOf('b=TIAS:') === 0) {
+      bandwidth = parseInt(bandwidth[0].substr(7), 10);
+    } else if (bandwidth[0].indexOf('b=AS:') === 0) {
+      // use formula from JSEP to convert b=AS to TIAS value.
+      bandwidth = parseInt(bandwidth[0].substr(5), 10) * 1000 * 0.95
+          - (50 * 40 * 8);
+    } else {
+      bandwidth = undefined;
+    }
+    encodingParameters.forEach(function(params) {
+      params.maxBitrate = bandwidth;
+    });
+  }
+  return encodingParameters;
+};
+
+// parses http://draft.ortc.org/#rtcrtcpparameters*
+SDPUtils.parseRtcpParameters = function(mediaSection) {
+  var rtcpParameters = {};
+
+  var cname;
+  // Gets the first SSRC. Note that with RTX there might be multiple
+  // SSRCs.
+  var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+      .map(function(line) {
+        return SDPUtils.parseSsrcMedia(line);
+      })
+      .filter(function(obj) {
+        return obj.attribute === 'cname';
+      })[0];
+  if (remoteSsrc) {
+    rtcpParameters.cname = remoteSsrc.value;
+    rtcpParameters.ssrc = remoteSsrc.ssrc;
+  }
+
+  // Edge uses the compound attribute instead of reducedSize
+  // compound is !reducedSize
+  var rsize = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-rsize');
+  rtcpParameters.reducedSize = rsize.length > 0;
+  rtcpParameters.compound = rsize.length === 0;
+
+  // parses the rtcp-mux attrіbute.
+  // Note that Edge does not support unmuxed RTCP.
+  var mux = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-mux');
+  rtcpParameters.mux = mux.length > 0;
+
+  return rtcpParameters;
+};
+
+// parses either a=msid: or a=ssrc:... msid lines and returns
+// the id of the MediaStream and MediaStreamTrack.
+SDPUtils.parseMsid = function(mediaSection) {
+  var parts;
+  var spec = SDPUtils.matchPrefix(mediaSection, 'a=msid:');
+  if (spec.length === 1) {
+    parts = spec[0].substr(7).split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+  var planB = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'msid';
+  });
+  if (planB.length > 0) {
+    parts = planB[0].value.split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+};
+
+// Generate a session ID for SDP.
+// https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-20#section-5.2.1
+// recommends using a cryptographically random +ve 64-bit value
+// but right now this should be acceptable and within the right range
+SDPUtils.generateSessionId = function() {
+  return Math.random().toString().substr(2, 21);
+};
+
+// Write boilder plate for start of SDP
+// sessId argument is optional - if not supplied it will
+// be generated randomly
+// sessVersion is optional and defaults to 2
+SDPUtils.writeSessionBoilerplate = function(sessId, sessVer) {
+  var sessionId;
+  var version = sessVer !== undefined ? sessVer : 2;
+  if (sessId) {
+    sessionId = sessId;
+  } else {
+    sessionId = SDPUtils.generateSessionId();
+  }
+  // FIXME: sess-id should be an NTP timestamp.
+  return 'v=0\r\n' +
+      'o=thisisadapterortc ' + sessionId + ' ' + version + ' IN IP4 127.0.0.1\r\n' +
+      's=-\r\n' +
+      't=0 0\r\n';
+};
+
+SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+};
+
+// Gets the direction from the mediaSection or the sessionpart.
+SDPUtils.getDirection = function(mediaSection, sessionpart) {
+  // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
+  var lines = SDPUtils.splitLines(mediaSection);
+  for (var i = 0; i < lines.length; i++) {
+    switch (lines[i]) {
+      case 'a=sendrecv':
+      case 'a=sendonly':
+      case 'a=recvonly':
+      case 'a=inactive':
+        return lines[i].substr(2);
+      default:
+        // FIXME: What should happen here?
+    }
+  }
+  if (sessionpart) {
+    return SDPUtils.getDirection(sessionpart);
+  }
+  return 'sendrecv';
+};
+
+SDPUtils.getKind = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return mline[0].substr(2);
+};
+
+SDPUtils.isRejected = function(mediaSection) {
+  return mediaSection.split(' ', 2)[1] === '0';
+};
+
+SDPUtils.parseMLine = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return {
+    kind: mline[0].substr(2),
+    port: parseInt(mline[1], 10),
+    protocol: mline[2],
+    fmt: mline.slice(3).join(' ')
+  };
+};
+
+// Expose public methods.
+if (typeof module === 'object') {
+  module.exports = SDPUtils;
+}
+
+},{}],3:[function(require,module,exports){
+(function (global){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var adapterFactory = require('./adapter_factory.js');
+module.exports = adapterFactory({window: global.window});
+
+}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
+},{"./adapter_factory.js":4}],4:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var utils = require('./utils');
+// Shimming starts here.
+module.exports = function(dependencies, opts) {
+  var window = dependencies && dependencies.window;
+
+  var options = {
+    shimChrome: true,
+    shimFirefox: true,
+    shimEdge: true,
+    shimSafari: true,
+  };
+
+  for (var key in opts) {
+    if (hasOwnProperty.call(opts, key)) {
+      options[key] = opts[key];
+    }
+  }
+
+  // Utils.
+  var logging = utils.log;
+  var browserDetails = utils.detectBrowser(window);
+
+  // Export to the adapter global object visible in the browser.
+  var adapter = {
+    browserDetails: browserDetails,
+    extractVersion: utils.extractVersion,
+    disableLog: utils.disableLog,
+    disableWarnings: utils.disableWarnings
+  };
+
+  // Uncomment the line below if you want logging to occur, including logging
+  // for the switch statement below. Can also be turned on in the browser via
+  // adapter.disableLog(false), but then logging from the switch statement below
+  // will not appear.
+  // require('./utils').disableLog(false);
+
+  // Browser shims.
+  var chromeShim = require('./chrome/chrome_shim') || null;
+  var edgeShim = require('./edge/edge_shim') || null;
+  var firefoxShim = require('./firefox/firefox_shim') || null;
+  var safariShim = require('./safari/safari_shim') || null;
+  var commonShim = require('./common_shim') || null;
+
+  // Shim browser if found.
+  switch (browserDetails.browser) {
+    case 'chrome':
+      if (!chromeShim || !chromeShim.shimPeerConnection ||
+          !options.shimChrome) {
+        logging('Chrome shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      chromeShim.shimGetUserMedia(window);
+      chromeShim.shimMediaStream(window);
+      chromeShim.shimSourceObject(window);
+      chromeShim.shimPeerConnection(window);
+      chromeShim.shimOnTrack(window);
+      chromeShim.shimAddTrackRemoveTrack(window);
+      chromeShim.shimGetSendersWithDtmf(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'firefox':
+      if (!firefoxShim || !firefoxShim.shimPeerConnection ||
+          !options.shimFirefox) {
+        logging('Firefox shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming firefox.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = firefoxShim;
+      commonShim.shimCreateObjectURL(window);
+
+      firefoxShim.shimGetUserMedia(window);
+      firefoxShim.shimSourceObject(window);
+      firefoxShim.shimPeerConnection(window);
+      firefoxShim.shimOnTrack(window);
+      firefoxShim.shimRemoveStream(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'edge':
+      if (!edgeShim || !edgeShim.shimPeerConnection || !options.shimEdge) {
+        logging('MS edge shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming edge.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = edgeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      edgeShim.shimGetUserMedia(window);
+      edgeShim.shimPeerConnection(window);
+      edgeShim.shimReplaceTrack(window);
+
+      // the edge shim implements the full RTCIceCandidate object.
+      break;
+    case 'safari':
+      if (!safariShim || !options.shimSafari) {
+        logging('Safari shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming safari.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = safariShim;
+      commonShim.shimCreateObjectURL(window);
+
+      safariShim.shimRTCIceServerUrls(window);
+      safariShim.shimCallbacksAPI(window);
+      safariShim.shimLocalStreamsAPI(window);
+      safariShim.shimRemoteStreamsAPI(window);
+      safariShim.shimTrackEventTransceiver(window);
+      safariShim.shimGetUserMedia(window);
+      safariShim.shimCreateOfferLegacy(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+
+  return adapter;
+};
+
+},{"./chrome/chrome_shim":5,"./common_shim":7,"./edge/edge_shim":8,"./firefox/firefox_shim":10,"./safari/safari_shim":12,"./utils":13}],5:[function(require,module,exports){
+
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+var chromeShim = {
+  shimMediaStream: function(window) {
+    window.MediaStream = window.MediaStream || window.webkitMediaStream;
+  },
+
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+          }
+          this.addEventListener('track', this._ontrack = f);
+        }
+      });
+      var origSetRemoteDescription =
+          window.RTCPeerConnection.prototype.setRemoteDescription;
+      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
+        var pc = this;
+        if (!pc._ontrackpoly) {
+          pc._ontrackpoly = function(e) {
+            // onaddstream does not fire when a track is added to an existing
+            // stream. But stream.onaddtrack is implemented so we use that.
+            e.stream.addEventListener('addtrack', function(te) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === te.track.id;
+                });
+              } else {
+                receiver = {track: te.track};
+              }
+
+              var event = new Event('track');
+              event.track = te.track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+            e.stream.getTracks().forEach(function(track) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === track.id;
+                });
+              } else {
+                receiver = {track: track};
+              }
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+          };
+          pc.addEventListener('addstream', pc._ontrackpoly);
+        }
+        return origSetRemoteDescription.apply(pc, arguments);
+      };
+    }
+  },
+
+  shimGetSendersWithDtmf: function(window) {
+    // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        !('getSenders' in window.RTCPeerConnection.prototype) &&
+        'createDTMFSender' in window.RTCPeerConnection.prototype) {
+      var shimSenderWithDtmf = function(pc, track) {
+        return {
+          track: track,
+          get dtmf() {
+            if (this._dtmf === undefined) {
+              if (track.kind === 'audio') {
+                this._dtmf = pc.createDTMFSender(track);
+              } else {
+                this._dtmf = null;
+              }
+            }
+            return this._dtmf;
+          },
+          _pc: pc
+        };
+      };
+
+      // augment addTrack when getSenders is not available.
+      if (!window.RTCPeerConnection.prototype.getSenders) {
+        window.RTCPeerConnection.prototype.getSenders = function() {
+          this._senders = this._senders || [];
+          return this._senders.slice(); // return a copy of the internal state.
+        };
+        var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+        window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+          var pc = this;
+          var sender = origAddTrack.apply(pc, arguments);
+          if (!sender) {
+            sender = shimSenderWithDtmf(pc, track);
+            pc._senders.push(sender);
+          }
+          return sender;
+        };
+
+        var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+        window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+          var pc = this;
+          origRemoveTrack.apply(pc, arguments);
+          var idx = pc._senders.indexOf(sender);
+          if (idx !== -1) {
+            pc._senders.splice(idx, 1);
+          }
+        };
+      }
+      var origAddStream = window.RTCPeerConnection.prototype.addStream;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origAddStream.apply(pc, [stream]);
+        stream.getTracks().forEach(function(track) {
+          pc._senders.push(shimSenderWithDtmf(pc, track));
+        });
+      };
+
+      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origRemoveStream.apply(pc, [stream]);
+
+        stream.getTracks().forEach(function(track) {
+          var sender = pc._senders.find(function(s) {
+            return s.track === track;
+          });
+          if (sender) {
+            pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
+          }
+        });
+      };
+    } else if (typeof window === 'object' && window.RTCPeerConnection &&
+               'getSenders' in window.RTCPeerConnection.prototype &&
+               'createDTMFSender' in window.RTCPeerConnection.prototype &&
+               window.RTCRtpSender &&
+               !('dtmf' in window.RTCRtpSender.prototype)) {
+      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+      window.RTCPeerConnection.prototype.getSenders = function() {
+        var pc = this;
+        var senders = origGetSenders.apply(pc, []);
+        senders.forEach(function(sender) {
+          sender._pc = pc;
+        });
+        return senders;
+      };
+
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = this._pc.createDTMFSender(this.track);
+            } else {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    var URL = window && window.URL;
+
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this._srcObject;
+          },
+          set: function(stream) {
+            var self = this;
+            // Use _srcObject as a private property for this shim
+            this._srcObject = stream;
+            if (this.src) {
+              URL.revokeObjectURL(this.src);
+            }
+
+            if (!stream) {
+              this.src = '';
+              return undefined;
+            }
+            this.src = URL.createObjectURL(stream);
+            // We need to recreate the blob url when a track is added or
+            // removed. Doing it manually since we want to avoid a recursion.
+            stream.addEventListener('addtrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+            stream.addEventListener('removetrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+          }
+        });
+      }
+    }
+  },
+
+  shimAddTrackRemoveTrack: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+    // shim addTrack and removeTrack.
+    if (window.RTCPeerConnection.prototype.addTrack &&
+        browserDetails.version >= 64) {
+      return;
+    }
+
+    // also shim pc.getLocalStreams when addTrack is shimmed
+    // to return the original streams.
+    var origGetLocalStreams = window.RTCPeerConnection.prototype
+        .getLocalStreams;
+    window.RTCPeerConnection.prototype.getLocalStreams = function() {
+      var self = this;
+      var nativeStreams = origGetLocalStreams.apply(this);
+      self._reverseStreams = self._reverseStreams || {};
+      return nativeStreams.map(function(stream) {
+        return self._reverseStreams[stream.id];
+      });
+    };
+
+    var origAddStream = window.RTCPeerConnection.prototype.addStream;
+    window.RTCPeerConnection.prototype.addStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      stream.getTracks().forEach(function(track) {
+        var alreadyExists = pc.getSenders().find(function(s) {
+          return s.track === track;
+        });
+        if (alreadyExists) {
+          throw new DOMException('Track already exists.',
+              'InvalidAccessError');
+        }
+      });
+      // Add identity mapping for consistency with addTrack.
+      // Unless this is being used with a stream from addTrack.
+      if (!pc._reverseStreams[stream.id]) {
+        var newStream = new window.MediaStream(stream.getTracks());
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        stream = newStream;
+      }
+      origAddStream.apply(pc, [stream]);
+    };
+
+    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
+      delete pc._reverseStreams[(pc._streams[stream.id] ?
+          pc._streams[stream.id].id : stream.id)];
+      delete pc._streams[stream.id];
+    };
+
+    window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      var streams = [].slice.call(arguments, 1);
+      if (streams.length !== 1 ||
+          !streams[0].getTracks().find(function(t) {
+            return t === track;
+          })) {
+        // this is not fully correct but all we can manage without
+        // [[associated MediaStreams]] internal slot.
+        throw new DOMException(
+          'The adapter.js addTrack polyfill only supports a single ' +
+          ' stream which is associated with the specified track.',
+          'NotSupportedError');
+      }
+
+      var alreadyExists = pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+            'InvalidAccessError');
+      }
+
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+      var oldStream = pc._streams[stream.id];
+      if (oldStream) {
+        // this is using odd Chrome behaviour, use with caution:
+        // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
+        // Note: we rely on the high-level addTrack/dtmf shim to
+        // create the sender with a dtmf sender.
+        oldStream.addTrack(track);
+
+        // Trigger ONN async.
+        Promise.resolve().then(function() {
+          pc.dispatchEvent(new Event('negotiationneeded'));
+        });
+      } else {
+        var newStream = new window.MediaStream([track]);
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        pc.addStream(newStream);
+      }
+      return pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+    };
+
+    // replace the internal stream id with the external one and
+    // vice versa.
+    function replaceInternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
+            externalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    function replaceExternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
+            internalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    ['createOffer', 'createAnswer'].forEach(function(method) {
+      var nativeMethod = window.RTCPeerConnection.prototype[method];
+      window.RTCPeerConnection.prototype[method] = function() {
+        var pc = this;
+        var args = arguments;
+        var isLegacyCall = arguments.length &&
+            typeof arguments[0] === 'function';
+        if (isLegacyCall) {
+          return nativeMethod.apply(pc, [
+            function(description) {
+              var desc = replaceInternalStreamId(pc, description);
+              args[0].apply(null, [desc]);
+            },
+            function(err) {
+              if (args[1]) {
+                args[1].apply(null, err);
+              }
+            }, arguments[2]
+          ]);
+        }
+        return nativeMethod.apply(pc, arguments)
+        .then(function(description) {
+          return replaceInternalStreamId(pc, description);
+        });
+      };
+    });
+
+    var origSetLocalDescription =
+        window.RTCPeerConnection.prototype.setLocalDescription;
+    window.RTCPeerConnection.prototype.setLocalDescription = function() {
+      var pc = this;
+      if (!arguments.length || !arguments[0].type) {
+        return origSetLocalDescription.apply(pc, arguments);
+      }
+      arguments[0] = replaceExternalStreamId(pc, arguments[0]);
+      return origSetLocalDescription.apply(pc, arguments);
+    };
+
+    // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
+
+    var origLocalDescription = Object.getOwnPropertyDescriptor(
+        window.RTCPeerConnection.prototype, 'localDescription');
+    Object.defineProperty(window.RTCPeerConnection.prototype,
+        'localDescription', {
+          get: function() {
+            var pc = this;
+            var description = origLocalDescription.get.apply(this);
+            if (description.type === '') {
+              return description;
+            }
+            return replaceInternalStreamId(pc, description);
+          }
+        });
+
+    window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      // We can not yet check for sender instanceof RTCRtpSender
+      // since we shim RTPSender. So we check if sender._pc is set.
+      if (!sender._pc) {
+        throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
+            'does not implement interface RTCRtpSender.', 'TypeError');
+      }
+      var isLocal = sender._pc === pc;
+      if (!isLocal) {
+        throw new DOMException('Sender was not created by this connection.',
+            'InvalidAccessError');
+      }
+
+      // Search for the native stream the senders track belongs to.
+      pc._streams = pc._streams || {};
+      var stream;
+      Object.keys(pc._streams).forEach(function(streamid) {
+        var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
+          return sender.track === track;
+        });
+        if (hasTrack) {
+          stream = pc._streams[streamid];
+        }
+      });
+
+      if (stream) {
+        if (stream.getTracks().length === 1) {
+          // if this is the last track of the stream, remove the stream. This
+          // takes care of any shimmed _senders.
+          pc.removeStream(pc._reverseStreams[stream.id]);
+        } else {
+          // relying on the same odd chrome behaviour as above.
+          stream.removeTrack(sender.track);
+        }
+        pc.dispatchEvent(new Event('negotiationneeded'));
+      }
+    };
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        // Translate iceTransportPolicy to iceTransports,
+        // see https://code.google.com/p/webrtc/issues/detail?id=4869
+        // this was fixed in M56 along with unprefixing RTCPeerConnection.
+        logging('PeerConnection');
+        if (pcConfig && pcConfig.iceTransportPolicy) {
+          pcConfig.iceTransports = pcConfig.iceTransportPolicy;
+        }
+
+        return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.webkitRTCPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      if (window.webkitRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.webkitRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+    } else {
+      // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+      var OrigPeerConnection = window.RTCPeerConnection;
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (pcConfig && pcConfig.iceServers) {
+          var newIceServers = [];
+          for (var i = 0; i < pcConfig.iceServers.length; i++) {
+            var server = pcConfig.iceServers[i];
+            if (!server.hasOwnProperty('urls') &&
+                server.hasOwnProperty('url')) {
+              utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+              server = JSON.parse(JSON.stringify(server));
+              server.urls = server.url;
+              newIceServers.push(server);
+            } else {
+              newIceServers.push(pcConfig.iceServers[i]);
+            }
+          }
+          pcConfig.iceServers = newIceServers;
+        }
+        return new OrigPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+
+    var origGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(selector,
+        successCallback, errorCallback) {
+      var self = this;
+      var args = arguments;
+
+      // If selector is a function then we are in the old style stats so just
+      // pass back the original getStats format to avoid breaking old users.
+      if (arguments.length > 0 && typeof selector === 'function') {
+        return origGetStats.apply(this, arguments);
+      }
+
+      // When spec-style getStats is supported, return those when called with
+      // either no arguments or the selector argument is null.
+      if (origGetStats.length === 0 && (arguments.length === 0 ||
+          typeof arguments[0] !== 'function')) {
+        return origGetStats.apply(this, []);
+      }
+
+      var fixChromeStats_ = function(response) {
+        var standardReport = {};
+        var reports = response.result();
+        reports.forEach(function(report) {
+          var standardStats = {
+            id: report.id,
+            timestamp: report.timestamp,
+            type: {
+              localcandidate: 'local-candidate',
+              remotecandidate: 'remote-candidate'
+            }[report.type] || report.type
+          };
+          report.names().forEach(function(name) {
+            standardStats[name] = report.stat(name);
+          });
+          standardReport[standardStats.id] = standardStats;
+        });
+
+        return standardReport;
+      };
+
+      // shim getStats with maplike support
+      var makeMapStats = function(stats) {
+        return new Map(Object.keys(stats).map(function(key) {
+          return [key, stats[key]];
+        }));
+      };
+
+      if (arguments.length >= 2) {
+        var successCallbackWrapper_ = function(response) {
+          args[1](makeMapStats(fixChromeStats_(response)));
+        };
+
+        return origGetStats.apply(this, [successCallbackWrapper_,
+          arguments[0]]);
+      }
+
+      // promise-support
+      return new Promise(function(resolve, reject) {
+        origGetStats.apply(self, [
+          function(response) {
+            resolve(makeMapStats(fixChromeStats_(response)));
+          }, reject]);
+      }).then(successCallback, errorCallback);
+    };
+
+    // add promise support -- natively available in Chrome 51
+    if (browserDetails.version < 51) {
+      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+          .forEach(function(method) {
+            var nativeMethod = window.RTCPeerConnection.prototype[method];
+            window.RTCPeerConnection.prototype[method] = function() {
+              var args = arguments;
+              var self = this;
+              var promise = new Promise(function(resolve, reject) {
+                nativeMethod.apply(self, [args[0], resolve, reject]);
+              });
+              if (args.length < 2) {
+                return promise;
+              }
+              return promise.then(function() {
+                args[1].apply(null, []);
+              },
+              function(err) {
+                if (args.length >= 3) {
+                  args[2].apply(null, [err]);
+                }
+              });
+            };
+          });
+    }
+
+    // promise support for createOffer and createAnswer. Available (without
+    // bugs) since M52: crbug/619289
+    if (browserDetails.version < 52) {
+      ['createOffer', 'createAnswer'].forEach(function(method) {
+        var nativeMethod = window.RTCPeerConnection.prototype[method];
+        window.RTCPeerConnection.prototype[method] = function() {
+          var self = this;
+          if (arguments.length < 1 || (arguments.length === 1 &&
+              typeof arguments[0] === 'object')) {
+            var opts = arguments.length === 1 ? arguments[0] : undefined;
+            return new Promise(function(resolve, reject) {
+              nativeMethod.apply(self, [resolve, reject, opts]);
+            });
+          }
+          return nativeMethod.apply(this, arguments);
+        };
+      });
+    }
+
+    // shim implicit creation of RTCSessionDescription/RTCIceCandidate
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+  }
+};
+
+
+// Expose public methods.
+module.exports = {
+  shimMediaStream: chromeShim.shimMediaStream,
+  shimOnTrack: chromeShim.shimOnTrack,
+  shimAddTrackRemoveTrack: chromeShim.shimAddTrackRemoveTrack,
+  shimGetSendersWithDtmf: chromeShim.shimGetSendersWithDtmf,
+  shimSourceObject: chromeShim.shimSourceObject,
+  shimPeerConnection: chromeShim.shimPeerConnection,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils.js":13,"./getusermedia":6}],6:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+
+  var constraintsToChrome_ = function(c) {
+    if (typeof c !== 'object' || c.mandatory || c.optional) {
+      return c;
+    }
+    var cc = {};
+    Object.keys(c).forEach(function(key) {
+      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+        return;
+      }
+      var r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
+      if (r.exact !== undefined && typeof r.exact === 'number') {
+        r.min = r.max = r.exact;
+      }
+      var oldname_ = function(prefix, name) {
+        if (prefix) {
+          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+        }
+        return (name === 'deviceId') ? 'sourceId' : name;
+      };
+      if (r.ideal !== undefined) {
+        cc.optional = cc.optional || [];
+        var oc = {};
+        if (typeof r.ideal === 'number') {
+          oc[oldname_('min', key)] = r.ideal;
+          cc.optional.push(oc);
+          oc = {};
+          oc[oldname_('max', key)] = r.ideal;
+          cc.optional.push(oc);
+        } else {
+          oc[oldname_('', key)] = r.ideal;
+          cc.optional.push(oc);
+        }
+      }
+      if (r.exact !== undefined && typeof r.exact !== 'number') {
+        cc.mandatory = cc.mandatory || {};
+        cc.mandatory[oldname_('', key)] = r.exact;
+      } else {
+        ['min', 'max'].forEach(function(mix) {
+          if (r[mix] !== undefined) {
+            cc.mandatory = cc.mandatory || {};
+            cc.mandatory[oldname_(mix, key)] = r[mix];
+          }
+        });
+      }
+    });
+    if (c.advanced) {
+      cc.optional = (cc.optional || []).concat(c.advanced);
+    }
+    return cc;
+  };
+
+  var shimConstraints_ = function(constraints, func) {
+    if (browserDetails.version >= 61) {
+      return func(constraints);
+    }
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (constraints && typeof constraints.audio === 'object') {
+      var remap = function(obj, a, b) {
+        if (a in obj && !(b in obj)) {
+          obj[b] = obj[a];
+          delete obj[a];
+        }
+      };
+      constraints = JSON.parse(JSON.stringify(constraints));
+      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
+      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
+      constraints.audio = constraintsToChrome_(constraints.audio);
+    }
+    if (constraints && typeof constraints.video === 'object') {
+      // Shim facingMode for mobile & surface pro.
+      var face = constraints.video.facingMode;
+      face = face && ((typeof face === 'object') ? face : {ideal: face});
+      var getSupportedFacingModeLies = browserDetails.version < 66;
+
+      if ((face && (face.exact === 'user' || face.exact === 'environment' ||
+                    face.ideal === 'user' || face.ideal === 'environment')) &&
+          !(navigator.mediaDevices.getSupportedConstraints &&
+            navigator.mediaDevices.getSupportedConstraints().facingMode &&
+            !getSupportedFacingModeLies)) {
+        delete constraints.video.facingMode;
+        var matches;
+        if (face.exact === 'environment' || face.ideal === 'environment') {
+          matches = ['back', 'rear'];
+        } else if (face.exact === 'user' || face.ideal === 'user') {
+          matches = ['front'];
+        }
+        if (matches) {
+          // Look for matches in label, or use last cam for back (typical).
+          return navigator.mediaDevices.enumerateDevices()
+          .then(function(devices) {
+            devices = devices.filter(function(d) {
+              return d.kind === 'videoinput';
+            });
+            var dev = devices.find(function(d) {
+              return matches.some(function(match) {
+                return d.label.toLowerCase().indexOf(match) !== -1;
+              });
+            });
+            if (!dev && devices.length && matches.indexOf('back') !== -1) {
+              dev = devices[devices.length - 1]; // more likely the back cam
+            }
+            if (dev) {
+              constraints.video.deviceId = face.exact ? {exact: dev.deviceId} :
+                                                        {ideal: dev.deviceId};
+            }
+            constraints.video = constraintsToChrome_(constraints.video);
+            logging('chrome: ' + JSON.stringify(constraints));
+            return func(constraints);
+          });
+        }
+      }
+      constraints.video = constraintsToChrome_(constraints.video);
+    }
+    logging('chrome: ' + JSON.stringify(constraints));
+    return func(constraints);
+  };
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        PermissionDeniedError: 'NotAllowedError',
+        InvalidStateError: 'NotReadableError',
+        DevicesNotFoundError: 'NotFoundError',
+        ConstraintNotSatisfiedError: 'OverconstrainedError',
+        TrackStartError: 'NotReadableError',
+        MediaDeviceFailedDueToShutdown: 'NotReadableError',
+        MediaDeviceKillSwitchOn: 'NotReadableError'
+      }[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraintName,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    shimConstraints_(constraints, function(c) {
+      navigator.webkitGetUserMedia(c, onSuccess, function(e) {
+        if (onError) {
+          onError(shimError_(e));
+        }
+      });
+    });
+  };
+
+  navigator.getUserMedia = getUserMedia_;
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      navigator.getUserMedia(constraints, resolve, reject);
+    });
+  };
+
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {
+      getUserMedia: getUserMediaPromise_,
+      enumerateDevices: function() {
+        return new Promise(function(resolve) {
+          var kinds = {audio: 'audioinput', video: 'videoinput'};
+          return window.MediaStreamTrack.getSources(function(devices) {
+            resolve(devices.map(function(device) {
+              return {label: device.label,
+                kind: kinds[device.kind],
+                deviceId: device.id,
+                groupId: ''};
+            }));
+          });
+        });
+      },
+      getSupportedConstraints: function() {
+        return {
+          deviceId: true, echoCancellation: true, facingMode: true,
+          frameRate: true, height: true, width: true
+        };
+      }
+    };
+  }
+
+  // A shim for getUserMedia method on the mediaDevices object.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (!navigator.mediaDevices.getUserMedia) {
+    navigator.mediaDevices.getUserMedia = function(constraints) {
+      return getUserMediaPromise_(constraints);
+    };
+  } else {
+    // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
+    // function which returns a Promise, it does not accept spec-style
+    // constraints.
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(cs) {
+      return shimConstraints_(cs, function(c) {
+        return origGetUserMedia(c).then(function(stream) {
+          if (c.audio && !stream.getAudioTracks().length ||
+              c.video && !stream.getVideoTracks().length) {
+            stream.getTracks().forEach(function(track) {
+              track.stop();
+            });
+            throw new DOMException('', 'NotFoundError');
+          }
+          return stream;
+        }, function(e) {
+          return Promise.reject(shimError_(e));
+        });
+      });
+    };
+  }
+
+  // Dummy devicechange event methods.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
+    navigator.mediaDevices.addEventListener = function() {
+      logging('Dummy mediaDevices.addEventListener called.');
+    };
+  }
+  if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
+    navigator.mediaDevices.removeEventListener = function() {
+      logging('Dummy mediaDevices.removeEventListener called.');
+    };
+  }
+};
+
+},{"../utils.js":13}],7:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+var utils = require('./utils');
+
+// Wraps the peerconnection event eventNameToWrap in a function
+// which returns the modified event object.
+function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  var proto = window.RTCPeerConnection.prototype;
+  var nativeAddEventListener = proto.addEventListener;
+  proto.addEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap) {
+      return nativeAddEventListener.apply(this, arguments);
+    }
+    var wrappedCallback = function(e) {
+      cb(wrapper(e));
+    };
+    this._eventMap = this._eventMap || {};
+    this._eventMap[cb] = wrappedCallback;
+    return nativeAddEventListener.apply(this, [nativeEventName,
+      wrappedCallback]);
+  };
+
+  var nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap
+        || !this._eventMap[cb]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    var unwrappedCb = this._eventMap[cb];
+    delete this._eventMap[cb];
+    return nativeRemoveEventListener.apply(this, [nativeEventName,
+      unwrappedCb]);
+  };
+
+  Object.defineProperty(proto, 'on' + eventNameToWrap, {
+    get: function() {
+      return this['_on' + eventNameToWrap];
+    },
+    set: function(cb) {
+      if (this['_on' + eventNameToWrap]) {
+        this.removeEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap]);
+        delete this['_on' + eventNameToWrap];
+      }
+      if (cb) {
+        this.addEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap] = cb);
+      }
+    }
+  });
+}
+
+module.exports = {
+  shimRTCIceCandidate: function(window) {
+    // foundation is arbitrarily chosen as an indicator for full support for
+    // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
+    if (window.RTCIceCandidate && 'foundation' in
+        window.RTCIceCandidate.prototype) {
+      return;
+    }
+
+    var NativeRTCIceCandidate = window.RTCIceCandidate;
+    window.RTCIceCandidate = function(args) {
+      // Remove the a= which shouldn't be part of the candidate string.
+      if (typeof args === 'object' && args.candidate &&
+          args.candidate.indexOf('a=') === 0) {
+        args = JSON.parse(JSON.stringify(args));
+        args.candidate = args.candidate.substr(2);
+      }
+
+      // Augment the native candidate with the parsed fields.
+      var nativeCandidate = new NativeRTCIceCandidate(args);
+      var parsedCandidate = SDPUtils.parseCandidate(args.candidate);
+      var augmentedCandidate = Object.assign(nativeCandidate,
+          parsedCandidate);
+
+      // Add a serializer that does not serialize the extra attributes.
+      augmentedCandidate.toJSON = function() {
+        return {
+          candidate: augmentedCandidate.candidate,
+          sdpMid: augmentedCandidate.sdpMid,
+          sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
+          usernameFragment: augmentedCandidate.usernameFragment,
+        };
+      };
+      return augmentedCandidate;
+    };
+
+    // Hook up the augmented candidate in onicecandidate and
+    // addEventListener('icecandidate', ...)
+    wrapPeerConnectionEvent(window, 'icecandidate', function(e) {
+      if (e.candidate) {
+        Object.defineProperty(e, 'candidate', {
+          value: new window.RTCIceCandidate(e.candidate),
+          writable: 'false'
+        });
+      }
+      return e;
+    });
+  },
+
+  // shimCreateObjectURL must be called before shimSourceObject to avoid loop.
+
+  shimCreateObjectURL: function(window) {
+    var URL = window && window.URL;
+
+    if (!(typeof window === 'object' && window.HTMLMediaElement &&
+          'srcObject' in window.HTMLMediaElement.prototype &&
+        URL.createObjectURL && URL.revokeObjectURL)) {
+      // Only shim CreateObjectURL using srcObject if srcObject exists.
+      return undefined;
+    }
+
+    var nativeCreateObjectURL = URL.createObjectURL.bind(URL);
+    var nativeRevokeObjectURL = URL.revokeObjectURL.bind(URL);
+    var streams = new Map(), newId = 0;
+
+    URL.createObjectURL = function(stream) {
+      if ('getTracks' in stream) {
+        var url = 'polyblob:' + (++newId);
+        streams.set(url, stream);
+        utils.deprecated('URL.createObjectURL(stream)',
+            'elem.srcObject = stream');
+        return url;
+      }
+      return nativeCreateObjectURL(stream);
+    };
+    URL.revokeObjectURL = function(url) {
+      nativeRevokeObjectURL(url);
+      streams.delete(url);
+    };
+
+    var dsc = Object.getOwnPropertyDescriptor(window.HTMLMediaElement.prototype,
+                                              'src');
+    Object.defineProperty(window.HTMLMediaElement.prototype, 'src', {
+      get: function() {
+        return dsc.get.apply(this);
+      },
+      set: function(url) {
+        this.srcObject = streams.get(url) || null;
+        return dsc.set.apply(this, [url]);
+      }
+    });
+
+    var nativeSetAttribute = window.HTMLMediaElement.prototype.setAttribute;
+    window.HTMLMediaElement.prototype.setAttribute = function() {
+      if (arguments.length === 2 &&
+          ('' + arguments[0]).toLowerCase() === 'src') {
+        this.srcObject = streams.get(arguments[1]) || null;
+      }
+      return nativeSetAttribute.apply(this, arguments);
+    };
+  }
+};
+
+},{"./utils":13,"sdp":2}],8:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var shimRTCPeerConnection = require('rtcpeerconnection-shim');
+
+module.exports = {
+  shimGetUserMedia: require('./getusermedia'),
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (window.RTCIceGatherer) {
+      // ORTC defines an RTCIceCandidate object but no constructor.
+      // Not implemented in Edge.
+      if (!window.RTCIceCandidate) {
+        window.RTCIceCandidate = function(args) {
+          return args;
+        };
+      }
+      // ORTC does not have a session description object but
+      // other browsers (i.e. Chrome) that will support both PC and ORTC
+      // in the future might have this defined already.
+      if (!window.RTCSessionDescription) {
+        window.RTCSessionDescription = function(args) {
+          return args;
+        };
+      }
+      // this adds an additional event listener to MediaStrackTrack that signals
+      // when a tracks enabled property was changed. Workaround for a bug in
+      // addStream, see below. No longer required in 15025+
+      if (browserDetails.version < 15025) {
+        var origMSTEnabled = Object.getOwnPropertyDescriptor(
+            window.MediaStreamTrack.prototype, 'enabled');
+        Object.defineProperty(window.MediaStreamTrack.prototype, 'enabled', {
+          set: function(value) {
+            origMSTEnabled.set.call(this, value);
+            var ev = new Event('enabled');
+            ev.enabled = value;
+            this.dispatchEvent(ev);
+          }
+        });
+      }
+    }
+
+    // ORTC defines the DTMF sender a bit different.
+    // https://github.com/w3c/ortc/issues/714
+    if (window.RTCRtpSender && !('dtmf' in window.RTCRtpSender.prototype)) {
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = new window.RTCDtmfSender(this);
+            } else if (this.track.kind === 'video') {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+
+    window.RTCPeerConnection =
+        shimRTCPeerConnection(window, browserDetails.version);
+  },
+  shimReplaceTrack: function(window) {
+    // ORTC has replaceTrack -- https://github.com/w3c/ortc/issues/614
+    if (window.RTCRtpSender &&
+        !('replaceTrack' in window.RTCRtpSender.prototype)) {
+      window.RTCRtpSender.prototype.replaceTrack =
+          window.RTCRtpSender.prototype.setTrack;
+    }
+  }
+};
+
+},{"../utils":13,"./getusermedia":9,"rtcpeerconnection-shim":1}],9:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+// Expose public methods.
+module.exports = function(window) {
+  var navigator = window && window.navigator;
+
+  var shimError_ = function(e) {
+    return {
+      name: {PermissionDeniedError: 'NotAllowedError'}[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name;
+      }
+    };
+  };
+
+  // getUserMedia error shim.
+  var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+      bind(navigator.mediaDevices);
+  navigator.mediaDevices.getUserMedia = function(c) {
+    return origGetUserMedia(c).catch(function(e) {
+      return Promise.reject(shimError_(e));
+    });
+  };
+};
+
+},{}],10:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+
+var firefoxShim = {
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+            this.removeEventListener('addstream', this._ontrackpoly);
+          }
+          this.addEventListener('track', this._ontrack = f);
+          this.addEventListener('addstream', this._ontrackpoly = function(e) {
+            e.stream.getTracks().forEach(function(track) {
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = {track: track};
+              event.transceiver = {receiver: event.receiver};
+              event.streams = [e.stream];
+              this.dispatchEvent(event);
+            }.bind(this));
+          }.bind(this));
+        }
+      });
+    }
+    if (typeof window === 'object' && window.RTCTrackEvent &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        !('transceiver' in window.RTCTrackEvent.prototype)) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this.mozSrcObject;
+          },
+          set: function(stream) {
+            this.mozSrcObject = stream;
+          }
+        });
+      }
+    }
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (typeof window !== 'object' || !(window.RTCPeerConnection ||
+        window.mozRTCPeerConnection)) {
+      return; // probably media.peerconnection.enabled=false in about:config
+    }
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (browserDetails.version < 38) {
+          // .urls is not supported in FF < 38.
+          // create RTCIceServers with a single url.
+          if (pcConfig && pcConfig.iceServers) {
+            var newIceServers = [];
+            for (var i = 0; i < pcConfig.iceServers.length; i++) {
+              var server = pcConfig.iceServers[i];
+              if (server.hasOwnProperty('urls')) {
+                for (var j = 0; j < server.urls.length; j++) {
+                  var newServer = {
+                    url: server.urls[j]
+                  };
+                  if (server.urls[j].indexOf('turn') === 0) {
+                    newServer.username = server.username;
+                    newServer.credential = server.credential;
+                  }
+                  newIceServers.push(newServer);
+                }
+              } else {
+                newIceServers.push(pcConfig.iceServers[i]);
+              }
+            }
+            pcConfig.iceServers = newIceServers;
+          }
+        }
+        return new window.mozRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.mozRTCPeerConnection.prototype;
+
+      // wrap static methods. Currently just generateCertificate.
+      if (window.mozRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.mozRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+
+      window.RTCSessionDescription = window.mozRTCSessionDescription;
+      window.RTCIceCandidate = window.mozRTCIceCandidate;
+    }
+
+    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+
+    // shim getStats with maplike support
+    var makeMapStats = function(stats) {
+      var map = new Map();
+      Object.keys(stats).forEach(function(key) {
+        map.set(key, stats[key]);
+        map[key] = stats[key];
+      });
+      return map;
+    };
+
+    var modernStatsTypes = {
+      inboundrtp: 'inbound-rtp',
+      outboundrtp: 'outbound-rtp',
+      candidatepair: 'candidate-pair',
+      localcandidate: 'local-candidate',
+      remotecandidate: 'remote-candidate'
+    };
+
+    var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(
+      selector,
+      onSucc,
+      onErr
+    ) {
+      return nativeGetStats.apply(this, [selector || null])
+        .then(function(stats) {
+          if (browserDetails.version < 48) {
+            stats = makeMapStats(stats);
+          }
+          if (browserDetails.version < 53 && !onSucc) {
+            // Shim only promise getStats with spec-hyphens in type names
+            // Leave callback version alone; misc old uses of forEach before Map
+            try {
+              stats.forEach(function(stat) {
+                stat.type = modernStatsTypes[stat.type] || stat.type;
+              });
+            } catch (e) {
+              if (e.name !== 'TypeError') {
+                throw e;
+              }
+              // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
+              stats.forEach(function(stat, i) {
+                stats.set(i, Object.assign({}, stat, {
+                  type: modernStatsTypes[stat.type] || stat.type
+                }));
+              });
+            }
+          }
+          return stats;
+        })
+        .then(onSucc, onErr);
+    };
+  },
+
+  shimRemoveStream: function(window) {
+    if (!window.RTCPeerConnection ||
+        'removeStream' in window.RTCPeerConnection.prototype) {
+      return;
+    }
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      utils.deprecated('removeStream', 'removeTrack');
+      this.getSenders().forEach(function(sender) {
+        if (sender.track && stream.getTracks().indexOf(sender.track) !== -1) {
+          pc.removeTrack(sender);
+        }
+      });
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimOnTrack: firefoxShim.shimOnTrack,
+  shimSourceObject: firefoxShim.shimSourceObject,
+  shimPeerConnection: firefoxShim.shimPeerConnection,
+  shimRemoveStream: firefoxShim.shimRemoveStream,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils":13,"./getusermedia":11}],11:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+  var MediaStreamTrack = window && window.MediaStreamTrack;
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        InternalError: 'NotReadableError',
+        NotSupportedError: 'TypeError',
+        PermissionDeniedError: 'NotAllowedError',
+        SecurityError: 'NotAllowedError'
+      }[e.name] || e.name,
+      message: {
+        'The operation is insecure.': 'The request is not allowed by the ' +
+        'user agent or the platform in the current context.'
+      }[e.message] || e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  // getUserMedia constraints shim.
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    var constraintsToFF37_ = function(c) {
+      if (typeof c !== 'object' || c.require) {
+        return c;
+      }
+      var require = [];
+      Object.keys(c).forEach(function(key) {
+        if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+          return;
+        }
+        var r = c[key] = (typeof c[key] === 'object') ?
+            c[key] : {ideal: c[key]};
+        if (r.min !== undefined ||
+            r.max !== undefined || r.exact !== undefined) {
+          require.push(key);
+        }
+        if (r.exact !== undefined) {
+          if (typeof r.exact === 'number') {
+            r. min = r.max = r.exact;
+          } else {
+            c[key] = r.exact;
+          }
+          delete r.exact;
+        }
+        if (r.ideal !== undefined) {
+          c.advanced = c.advanced || [];
+          var oc = {};
+          if (typeof r.ideal === 'number') {
+            oc[key] = {min: r.ideal, max: r.ideal};
+          } else {
+            oc[key] = r.ideal;
+          }
+          c.advanced.push(oc);
+          delete r.ideal;
+          if (!Object.keys(r).length) {
+            delete c[key];
+          }
+        }
+      });
+      if (require.length) {
+        c.require = require;
+      }
+      return c;
+    };
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (browserDetails.version < 38) {
+      logging('spec: ' + JSON.stringify(constraints));
+      if (constraints.audio) {
+        constraints.audio = constraintsToFF37_(constraints.audio);
+      }
+      if (constraints.video) {
+        constraints.video = constraintsToFF37_(constraints.video);
+      }
+      logging('ff37: ' + JSON.stringify(constraints));
+    }
+    return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
+      onError(shimError_(e));
+    });
+  };
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      getUserMedia_(constraints, resolve, reject);
+    });
+  };
+
+  // Shim for mediaDevices on older versions.
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
+      addEventListener: function() { },
+      removeEventListener: function() { }
+    };
+  }
+  navigator.mediaDevices.enumerateDevices =
+      navigator.mediaDevices.enumerateDevices || function() {
+        return new Promise(function(resolve) {
+          var infos = [
+            {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
+            {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
+          ];
+          resolve(infos);
+        });
+      };
+
+  if (browserDetails.version < 41) {
+    // Work around http://bugzil.la/1169665
+    var orgEnumerateDevices =
+        navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
+    navigator.mediaDevices.enumerateDevices = function() {
+      return orgEnumerateDevices().then(undefined, function(e) {
+        if (e.name === 'NotFoundError') {
+          return [];
+        }
+        throw e;
+      });
+    };
+  }
+  if (browserDetails.version < 49) {
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      return origGetUserMedia(c).then(function(stream) {
+        // Work around https://bugzil.la/802326
+        if (c.audio && !stream.getAudioTracks().length ||
+            c.video && !stream.getVideoTracks().length) {
+          stream.getTracks().forEach(function(track) {
+            track.stop();
+          });
+          throw new DOMException('The object can not be found here.',
+                                 'NotFoundError');
+        }
+        return stream;
+      }, function(e) {
+        return Promise.reject(shimError_(e));
+      });
+    };
+  }
+  if (!(browserDetails.version > 55 &&
+      'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
+    var remap = function(obj, a, b) {
+      if (a in obj && !(b in obj)) {
+        obj[b] = obj[a];
+        delete obj[a];
+      }
+    };
+
+    var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      if (typeof c === 'object' && typeof c.audio === 'object') {
+        c = JSON.parse(JSON.stringify(c));
+        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
+        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
+      }
+      return nativeGetUserMedia(c);
+    };
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
+      var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
+      MediaStreamTrack.prototype.getSettings = function() {
+        var obj = nativeGetSettings.apply(this, arguments);
+        remap(obj, 'mozAutoGainControl', 'autoGainControl');
+        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
+        return obj;
+      };
+    }
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
+      var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
+      MediaStreamTrack.prototype.applyConstraints = function(c) {
+        if (this.kind === 'audio' && typeof c === 'object') {
+          c = JSON.parse(JSON.stringify(c));
+          remap(c, 'autoGainControl', 'mozAutoGainControl');
+          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
+        }
+        return nativeApplyConstraints.apply(this, [c]);
+      };
+    }
+  }
+  navigator.getUserMedia = function(constraints, onSuccess, onError) {
+    if (browserDetails.version < 44) {
+      return getUserMedia_(constraints, onSuccess, onError);
+    }
+    // Replace Firefox 44+'s deprecation warning with unprefixed version.
+    utils.deprecated('navigator.getUserMedia',
+        'navigator.mediaDevices.getUserMedia');
+    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
+  };
+};
+
+},{"../utils":13}],12:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+'use strict';
+var utils = require('../utils');
+
+var safariShim = {
+  // TODO: DrAlex, should be here, double check against LayoutTests
+
+  // TODO: once the back-end for the mac port is done, add.
+  // TODO: check for webkitGTK+
+  // shimPeerConnection: function() { },
+
+  shimLocalStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getLocalStreams = function() {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        return this._localStreams;
+      };
+    }
+    if (!('getStreamById' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getStreamById = function(id) {
+        var result = null;
+        if (this._localStreams) {
+          this._localStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        if (this._remoteStreams) {
+          this._remoteStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        return result;
+      };
+    }
+    if (!('addStream' in window.RTCPeerConnection.prototype)) {
+      var _addTrack = window.RTCPeerConnection.prototype.addTrack;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        if (this._localStreams.indexOf(stream) === -1) {
+          this._localStreams.push(stream);
+        }
+        var self = this;
+        stream.getTracks().forEach(function(track) {
+          _addTrack.call(self, track, stream);
+        });
+      };
+
+      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+        if (stream) {
+          if (!this._localStreams) {
+            this._localStreams = [stream];
+          } else if (this._localStreams.indexOf(stream) === -1) {
+            this._localStreams.push(stream);
+          }
+        }
+        return _addTrack.call(this, track, stream);
+      };
+    }
+    if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        var index = this._localStreams.indexOf(stream);
+        if (index === -1) {
+          return;
+        }
+        this._localStreams.splice(index, 1);
+        var self = this;
+        var tracks = stream.getTracks();
+        this.getSenders().forEach(function(sender) {
+          if (tracks.indexOf(sender.track) !== -1) {
+            self.removeTrack(sender);
+          }
+        });
+      };
+    }
+  },
+  shimRemoteStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getRemoteStreams = function() {
+        return this._remoteStreams ? this._remoteStreams : [];
+      };
+    }
+    if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
+        get: function() {
+          return this._onaddstream;
+        },
+        set: function(f) {
+          if (this._onaddstream) {
+            this.removeEventListener('addstream', this._onaddstream);
+            this.removeEventListener('track', this._onaddstreampoly);
+          }
+          this.addEventListener('addstream', this._onaddstream = f);
+          this.addEventListener('track', this._onaddstreampoly = function(e) {
+            var stream = e.streams[0];
+            if (!this._remoteStreams) {
+              this._remoteStreams = [];
+            }
+            if (this._remoteStreams.indexOf(stream) >= 0) {
+              return;
+            }
+            this._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = e.streams[0];
+            this.dispatchEvent(event);
+          }.bind(this));
+        }
+      });
+    }
+  },
+  shimCallbacksAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    var prototype = window.RTCPeerConnection.prototype;
+    var createOffer = prototype.createOffer;
+    var createAnswer = prototype.createAnswer;
+    var setLocalDescription = prototype.setLocalDescription;
+    var setRemoteDescription = prototype.setRemoteDescription;
+    var addIceCandidate = prototype.addIceCandidate;
+
+    prototype.createOffer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createOffer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    prototype.createAnswer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createAnswer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    var withCallback = function(description, successCallback, failureCallback) {
+      var promise = setLocalDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setLocalDescription = withCallback;
+
+    withCallback = function(description, successCallback, failureCallback) {
+      var promise = setRemoteDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setRemoteDescription = withCallback;
+
+    withCallback = function(candidate, successCallback, failureCallback) {
+      var promise = addIceCandidate.apply(this, [candidate]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.addIceCandidate = withCallback;
+  },
+  shimGetUserMedia: function(window) {
+    var navigator = window && window.navigator;
+
+    if (!navigator.getUserMedia) {
+      if (navigator.webkitGetUserMedia) {
+        navigator.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
+      } else if (navigator.mediaDevices &&
+          navigator.mediaDevices.getUserMedia) {
+        navigator.getUserMedia = function(constraints, cb, errcb) {
+          navigator.mediaDevices.getUserMedia(constraints)
+          .then(cb, errcb);
+        }.bind(navigator);
+      }
+    }
+  },
+  shimRTCIceServerUrls: function(window) {
+    // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+    var OrigPeerConnection = window.RTCPeerConnection;
+    window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+      if (pcConfig && pcConfig.iceServers) {
+        var newIceServers = [];
+        for (var i = 0; i < pcConfig.iceServers.length; i++) {
+          var server = pcConfig.iceServers[i];
+          if (!server.hasOwnProperty('urls') &&
+              server.hasOwnProperty('url')) {
+            utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+            server = JSON.parse(JSON.stringify(server));
+            server.urls = server.url;
+            delete server.url;
+            newIceServers.push(server);
+          } else {
+            newIceServers.push(pcConfig.iceServers[i]);
+          }
+        }
+        pcConfig.iceServers = newIceServers;
+      }
+      return new OrigPeerConnection(pcConfig, pcConstraints);
+    };
+    window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+    // wrap static methods. Currently just generateCertificate.
+    if ('generateCertificate' in window.RTCPeerConnection) {
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+  },
+  shimTrackEventTransceiver: function(window) {
+    // Add event.transceiver member over deprecated event.receiver
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        // can't check 'transceiver' in window.RTCTrackEvent.prototype, as it is
+        // defined for some reason even when window.RTCTransceiver is not.
+        !window.RTCTransceiver) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimCreateOfferLegacy: function(window) {
+    var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+    window.RTCPeerConnection.prototype.createOffer = function(offerOptions) {
+      var pc = this;
+      if (offerOptions) {
+        var audioTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'audio';
+        });
+        if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
+          if (audioTransceiver.direction === 'sendrecv') {
+            audioTransceiver.setDirection('sendonly');
+          } else if (audioTransceiver.direction === 'recvonly') {
+            audioTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveAudio === true &&
+            !audioTransceiver) {
+          pc.addTransceiver('audio');
+        }
+
+        var videoTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'video';
+        });
+        if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
+          if (videoTransceiver.direction === 'sendrecv') {
+            videoTransceiver.setDirection('sendonly');
+          } else if (videoTransceiver.direction === 'recvonly') {
+            videoTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveVideo === true &&
+            !videoTransceiver) {
+          pc.addTransceiver('video');
+        }
+      }
+      return origCreateOffer.apply(pc, arguments);
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimCallbacksAPI: safariShim.shimCallbacksAPI,
+  shimLocalStreamsAPI: safariShim.shimLocalStreamsAPI,
+  shimRemoteStreamsAPI: safariShim.shimRemoteStreamsAPI,
+  shimGetUserMedia: safariShim.shimGetUserMedia,
+  shimRTCIceServerUrls: safariShim.shimRTCIceServerUrls,
+  shimTrackEventTransceiver: safariShim.shimTrackEventTransceiver,
+  shimCreateOfferLegacy: safariShim.shimCreateOfferLegacy
+  // TODO
+  // shimPeerConnection: safariShim.shimPeerConnection
+};
+
+},{"../utils":13}],13:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var logDisabled_ = true;
+var deprecationWarnings_ = true;
+
+// Utility methods.
+var utils = {
+  disableLog: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    logDisabled_ = bool;
+    return (bool) ? 'adapter.js logging disabled' :
+        'adapter.js logging enabled';
+  },
+
+  /**
+   * Disable or enable deprecation warnings
+   * @param {!boolean} bool set to true to disable warnings.
+   */
+  disableWarnings: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    deprecationWarnings_ = !bool;
+    return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
+  },
+
+  log: function() {
+    if (typeof window === 'object') {
+      if (logDisabled_) {
+        return;
+      }
+      if (typeof console !== 'undefined' && typeof console.log === 'function') {
+        console.log.apply(console, arguments);
+      }
+    }
+  },
+
+  /**
+   * Shows a deprecation warning suggesting the modern and spec-compatible API.
+   */
+  deprecated: function(oldMethod, newMethod) {
+    if (!deprecationWarnings_) {
+      return;
+    }
+    console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
+        ' instead.');
+  },
+
+  /**
+   * Extract browser version out of the provided user agent string.
+   *
+   * @param {!string} uastring userAgent string.
+   * @param {!string} expr Regular expression used as match criteria.
+   * @param {!number} pos position in the version string to be returned.
+   * @return {!number} browser version.
+   */
+  extractVersion: function(uastring, expr, pos) {
+    var match = uastring.match(expr);
+    return match && match.length >= pos && parseInt(match[pos], 10);
+  },
+
+  /**
+   * Browser detector.
+   *
+   * @return {object} result containing browser and version
+   *     properties.
+   */
+  detectBrowser: function(window) {
+    var navigator = window && window.navigator;
+
+    // Returned result object.
+    var result = {};
+    result.browser = null;
+    result.version = null;
+
+    // Fail early if it's not a browser
+    if (typeof window === 'undefined' || !window.navigator) {
+      result.browser = 'Not a browser.';
+      return result;
+    }
+
+    // Firefox.
+    if (navigator.mozGetUserMedia) {
+      result.browser = 'firefox';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Firefox\/(\d+)\./, 1);
+    } else if (navigator.webkitGetUserMedia) {
+      // Chrome, Chromium, Webview, Opera, all use the chrome shim for now
+      if (window.webkitRTCPeerConnection) {
+        result.browser = 'chrome';
+        result.version = this.extractVersion(navigator.userAgent,
+          /Chrom(e|ium)\/(\d+)\./, 2);
+      } else { // Safari (in an unpublished version) or unknown webkit-based.
+        if (navigator.userAgent.match(/Version\/(\d+).(\d+)/)) {
+          result.browser = 'safari';
+          result.version = this.extractVersion(navigator.userAgent,
+            /AppleWebKit\/(\d+)\./, 1);
+        } else { // unknown webkit-based browser.
+          result.browser = 'Unsupported webkit-based browser ' +
+              'with GUM support but no WebRTC support.';
+          return result;
+        }
+      }
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) { // Edge.
+      result.browser = 'edge';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Edge\/(\d+).(\d+)$/, 2);
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) {
+        // Safari, with webkitGetUserMedia removed.
+      result.browser = 'safari';
+      result.version = this.extractVersion(navigator.userAgent,
+          /AppleWebKit\/(\d+)\./, 1);
+    } else { // Default fallthrough: not supported.
+      result.browser = 'Not a supported browser.';
+      return result;
+    }
+
+    return result;
+  },
+
+};
+
+// Export.
+module.exports = {
+  log: utils.log,
+  deprecated: utils.deprecated,
+  disableLog: utils.disableLog,
+  disableWarnings: utils.disableWarnings,
+  extractVersion: utils.extractVersion,
+  shimCreateObjectURL: utils.shimCreateObjectURL,
+  detectBrowser: utils.detectBrowser.bind(utils)
+};
+
+},{}]},{},[3])(3)
+});

+ 2795 - 0
support/client/lib/vwf/view/webrtc/dist/adapter_no_edge.js

@@ -0,0 +1,2795 @@
+(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.adapter = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+
+},{}],2:[function(require,module,exports){
+ /* eslint-env node */
+'use strict';
+
+// SDP helpers.
+var SDPUtils = {};
+
+// Generate an alphanumeric identifier for cname or mids.
+// TODO: use UUIDs instead? https://gist.github.com/jed/982883
+SDPUtils.generateIdentifier = function() {
+  return Math.random().toString(36).substr(2, 10);
+};
+
+// The RTCP CNAME used by all peerconnections from the same JS.
+SDPUtils.localCName = SDPUtils.generateIdentifier();
+
+// Splits SDP into lines, dealing with both CRLF and LF.
+SDPUtils.splitLines = function(blob) {
+  return blob.trim().split('\n').map(function(line) {
+    return line.trim();
+  });
+};
+// Splits SDP into sessionpart and mediasections. Ensures CRLF.
+SDPUtils.splitSections = function(blob) {
+  var parts = blob.split('\nm=');
+  return parts.map(function(part, index) {
+    return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
+  });
+};
+
+// Returns lines that start with a certain prefix.
+SDPUtils.matchPrefix = function(blob, prefix) {
+  return SDPUtils.splitLines(blob).filter(function(line) {
+    return line.indexOf(prefix) === 0;
+  });
+};
+
+// Parses an ICE candidate line. Sample input:
+// candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8
+// rport 55996"
+SDPUtils.parseCandidate = function(line) {
+  var parts;
+  // Parse both variants.
+  if (line.indexOf('a=candidate:') === 0) {
+    parts = line.substring(12).split(' ');
+  } else {
+    parts = line.substring(10).split(' ');
+  }
+
+  var candidate = {
+    foundation: parts[0],
+    component: parseInt(parts[1], 10),
+    protocol: parts[2].toLowerCase(),
+    priority: parseInt(parts[3], 10),
+    ip: parts[4],
+    port: parseInt(parts[5], 10),
+    // skip parts[6] == 'typ'
+    type: parts[7]
+  };
+
+  for (var i = 8; i < parts.length; i += 2) {
+    switch (parts[i]) {
+      case 'raddr':
+        candidate.relatedAddress = parts[i + 1];
+        break;
+      case 'rport':
+        candidate.relatedPort = parseInt(parts[i + 1], 10);
+        break;
+      case 'tcptype':
+        candidate.tcpType = parts[i + 1];
+        break;
+      case 'ufrag':
+        candidate.ufrag = parts[i + 1]; // for backward compability.
+        candidate.usernameFragment = parts[i + 1];
+        break;
+      default: // extension handling, in particular ufrag
+        candidate[parts[i]] = parts[i + 1];
+        break;
+    }
+  }
+  return candidate;
+};
+
+// Translates a candidate object into SDP candidate attribute.
+SDPUtils.writeCandidate = function(candidate) {
+  var sdp = [];
+  sdp.push(candidate.foundation);
+  sdp.push(candidate.component);
+  sdp.push(candidate.protocol.toUpperCase());
+  sdp.push(candidate.priority);
+  sdp.push(candidate.ip);
+  sdp.push(candidate.port);
+
+  var type = candidate.type;
+  sdp.push('typ');
+  sdp.push(type);
+  if (type !== 'host' && candidate.relatedAddress &&
+      candidate.relatedPort) {
+    sdp.push('raddr');
+    sdp.push(candidate.relatedAddress); // was: relAddr
+    sdp.push('rport');
+    sdp.push(candidate.relatedPort); // was: relPort
+  }
+  if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
+    sdp.push('tcptype');
+    sdp.push(candidate.tcpType);
+  }
+  if (candidate.ufrag) {
+    sdp.push('ufrag');
+    sdp.push(candidate.ufrag);
+  }
+  return 'candidate:' + sdp.join(' ');
+};
+
+// Parses an ice-options line, returns an array of option tags.
+// a=ice-options:foo bar
+SDPUtils.parseIceOptions = function(line) {
+  return line.substr(14).split(' ');
+}
+
+// Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
+// a=rtpmap:111 opus/48000/2
+SDPUtils.parseRtpMap = function(line) {
+  var parts = line.substr(9).split(' ');
+  var parsed = {
+    payloadType: parseInt(parts.shift(), 10) // was: id
+  };
+
+  parts = parts[0].split('/');
+
+  parsed.name = parts[0];
+  parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
+  // was: channels
+  parsed.numChannels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
+  return parsed;
+};
+
+// Generate an a=rtpmap line from RTCRtpCodecCapability or
+// RTCRtpCodecParameters.
+SDPUtils.writeRtpMap = function(codec) {
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
+      (codec.numChannels !== 1 ? '/' + codec.numChannels : '') + '\r\n';
+};
+
+// Parses an a=extmap line (headerextension from RFC 5285). Sample input:
+// a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
+// a=extmap:2/sendonly urn:ietf:params:rtp-hdrext:toffset
+SDPUtils.parseExtmap = function(line) {
+  var parts = line.substr(9).split(' ');
+  return {
+    id: parseInt(parts[0], 10),
+    direction: parts[0].indexOf('/') > 0 ? parts[0].split('/')[1] : 'sendrecv',
+    uri: parts[1]
+  };
+};
+
+// Generates a=extmap line from RTCRtpHeaderExtensionParameters or
+// RTCRtpHeaderExtension.
+SDPUtils.writeExtmap = function(headerExtension) {
+  return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
+      (headerExtension.direction && headerExtension.direction !== 'sendrecv'
+          ? '/' + headerExtension.direction
+          : '') +
+      ' ' + headerExtension.uri + '\r\n';
+};
+
+// Parses an ftmp line, returns dictionary. Sample input:
+// a=fmtp:96 vbr=on;cng=on
+// Also deals with vbr=on; cng=on
+SDPUtils.parseFmtp = function(line) {
+  var parsed = {};
+  var kv;
+  var parts = line.substr(line.indexOf(' ') + 1).split(';');
+  for (var j = 0; j < parts.length; j++) {
+    kv = parts[j].trim().split('=');
+    parsed[kv[0].trim()] = kv[1];
+  }
+  return parsed;
+};
+
+// Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeFmtp = function(codec) {
+  var line = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.parameters && Object.keys(codec.parameters).length) {
+    var params = [];
+    Object.keys(codec.parameters).forEach(function(param) {
+      params.push(param + '=' + codec.parameters[param]);
+    });
+    line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
+  }
+  return line;
+};
+
+// Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
+// a=rtcp-fb:98 nack rpsi
+SDPUtils.parseRtcpFb = function(line) {
+  var parts = line.substr(line.indexOf(' ') + 1).split(' ');
+  return {
+    type: parts.shift(),
+    parameter: parts.join(' ')
+  };
+};
+// Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeRtcpFb = function(codec) {
+  var lines = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
+    // FIXME: special handling for trr-int?
+    codec.rtcpFeedback.forEach(function(fb) {
+      lines += 'a=rtcp-fb:' + pt + ' ' + fb.type +
+      (fb.parameter && fb.parameter.length ? ' ' + fb.parameter : '') +
+          '\r\n';
+    });
+  }
+  return lines;
+};
+
+// Parses an RFC 5576 ssrc media attribute. Sample input:
+// a=ssrc:3735928559 cname:something
+SDPUtils.parseSsrcMedia = function(line) {
+  var sp = line.indexOf(' ');
+  var parts = {
+    ssrc: parseInt(line.substr(7, sp - 7), 10)
+  };
+  var colon = line.indexOf(':', sp);
+  if (colon > -1) {
+    parts.attribute = line.substr(sp + 1, colon - sp - 1);
+    parts.value = line.substr(colon + 1);
+  } else {
+    parts.attribute = line.substr(sp + 1);
+  }
+  return parts;
+};
+
+// Extracts the MID (RFC 5888) from a media section.
+// returns the MID or undefined if no mid line was found.
+SDPUtils.getMid = function(mediaSection) {
+  var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0];
+  if (mid) {
+    return mid.substr(6);
+  }
+}
+
+SDPUtils.parseFingerprint = function(line) {
+  var parts = line.substr(14).split(' ');
+  return {
+    algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
+    value: parts[1]
+  };
+};
+
+// Extracts DTLS parameters from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the fingerprint line as input. See also getIceParameters.
+SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.matchPrefix(mediaSection + sessionpart,
+      'a=fingerprint:');
+  // Note: a=setup line is ignored since we use the 'auto' role.
+  // Note2: 'algorithm' is not case sensitive except in Edge.
+  return {
+    role: 'auto',
+    fingerprints: lines.map(SDPUtils.parseFingerprint)
+  };
+};
+
+// Serializes DTLS parameters to SDP.
+SDPUtils.writeDtlsParameters = function(params, setupType) {
+  var sdp = 'a=setup:' + setupType + '\r\n';
+  params.fingerprints.forEach(function(fp) {
+    sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
+  });
+  return sdp;
+};
+// Parses ICE information from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the ice-ufrag and ice-pwd lines as input.
+SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  // Search in session part, too.
+  lines = lines.concat(SDPUtils.splitLines(sessionpart));
+  var iceParameters = {
+    usernameFragment: lines.filter(function(line) {
+      return line.indexOf('a=ice-ufrag:') === 0;
+    })[0].substr(12),
+    password: lines.filter(function(line) {
+      return line.indexOf('a=ice-pwd:') === 0;
+    })[0].substr(10)
+  };
+  return iceParameters;
+};
+
+// Serializes ICE parameters to SDP.
+SDPUtils.writeIceParameters = function(params) {
+  return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
+      'a=ice-pwd:' + params.password + '\r\n';
+};
+
+// Parses the SDP media section and returns RTCRtpParameters.
+SDPUtils.parseRtpParameters = function(mediaSection) {
+  var description = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: [],
+    rtcp: []
+  };
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
+    var pt = mline[i];
+    var rtpmapline = SDPUtils.matchPrefix(
+        mediaSection, 'a=rtpmap:' + pt + ' ')[0];
+    if (rtpmapline) {
+      var codec = SDPUtils.parseRtpMap(rtpmapline);
+      var fmtps = SDPUtils.matchPrefix(
+          mediaSection, 'a=fmtp:' + pt + ' ');
+      // Only the first a=fmtp:<pt> is considered.
+      codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
+      codec.rtcpFeedback = SDPUtils.matchPrefix(
+          mediaSection, 'a=rtcp-fb:' + pt + ' ')
+        .map(SDPUtils.parseRtcpFb);
+      description.codecs.push(codec);
+      // parse FEC mechanisms from rtpmap lines.
+      switch (codec.name.toUpperCase()) {
+        case 'RED':
+        case 'ULPFEC':
+          description.fecMechanisms.push(codec.name.toUpperCase());
+          break;
+        default: // only RED and ULPFEC are recognized as FEC mechanisms.
+          break;
+      }
+    }
+  }
+  SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
+    description.headerExtensions.push(SDPUtils.parseExtmap(line));
+  });
+  // FIXME: parse rtcp.
+  return description;
+};
+
+// Generates parts of the SDP media section describing the capabilities /
+// parameters.
+SDPUtils.writeRtpDescription = function(kind, caps) {
+  var sdp = '';
+
+  // Build the mline.
+  sdp += 'm=' + kind + ' ';
+  sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
+  sdp += ' UDP/TLS/RTP/SAVPF ';
+  sdp += caps.codecs.map(function(codec) {
+    if (codec.preferredPayloadType !== undefined) {
+      return codec.preferredPayloadType;
+    }
+    return codec.payloadType;
+  }).join(' ') + '\r\n';
+
+  sdp += 'c=IN IP4 0.0.0.0\r\n';
+  sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';
+
+  // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
+  caps.codecs.forEach(function(codec) {
+    sdp += SDPUtils.writeRtpMap(codec);
+    sdp += SDPUtils.writeFmtp(codec);
+    sdp += SDPUtils.writeRtcpFb(codec);
+  });
+  var maxptime = 0;
+  caps.codecs.forEach(function(codec) {
+    if (codec.maxptime > maxptime) {
+      maxptime = codec.maxptime;
+    }
+  });
+  if (maxptime > 0) {
+    sdp += 'a=maxptime:' + maxptime + '\r\n';
+  }
+  sdp += 'a=rtcp-mux\r\n';
+
+  caps.headerExtensions.forEach(function(extension) {
+    sdp += SDPUtils.writeExtmap(extension);
+  });
+  // FIXME: write fecMechanisms.
+  return sdp;
+};
+
+// Parses the SDP media section and returns an array of
+// RTCRtpEncodingParameters.
+SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
+  var encodingParameters = [];
+  var description = SDPUtils.parseRtpParameters(mediaSection);
+  var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
+  var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;
+
+  // filter a=ssrc:... cname:, ignore PlanB-msid
+  var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'cname';
+  });
+  var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
+  var secondarySsrc;
+
+  var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
+  .map(function(line) {
+    var parts = line.split(' ');
+    parts.shift();
+    return parts.map(function(part) {
+      return parseInt(part, 10);
+    });
+  });
+  if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
+    secondarySsrc = flows[0][1];
+  }
+
+  description.codecs.forEach(function(codec) {
+    if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
+      var encParam = {
+        ssrc: primarySsrc,
+        codecPayloadType: parseInt(codec.parameters.apt, 10),
+        rtx: {
+          ssrc: secondarySsrc
+        }
+      };
+      encodingParameters.push(encParam);
+      if (hasRed) {
+        encParam = JSON.parse(JSON.stringify(encParam));
+        encParam.fec = {
+          ssrc: secondarySsrc,
+          mechanism: hasUlpfec ? 'red+ulpfec' : 'red'
+        };
+        encodingParameters.push(encParam);
+      }
+    }
+  });
+  if (encodingParameters.length === 0 && primarySsrc) {
+    encodingParameters.push({
+      ssrc: primarySsrc
+    });
+  }
+
+  // we support both b=AS and b=TIAS but interpret AS as TIAS.
+  var bandwidth = SDPUtils.matchPrefix(mediaSection, 'b=');
+  if (bandwidth.length) {
+    if (bandwidth[0].indexOf('b=TIAS:') === 0) {
+      bandwidth = parseInt(bandwidth[0].substr(7), 10);
+    } else if (bandwidth[0].indexOf('b=AS:') === 0) {
+      // use formula from JSEP to convert b=AS to TIAS value.
+      bandwidth = parseInt(bandwidth[0].substr(5), 10) * 1000 * 0.95
+          - (50 * 40 * 8);
+    } else {
+      bandwidth = undefined;
+    }
+    encodingParameters.forEach(function(params) {
+      params.maxBitrate = bandwidth;
+    });
+  }
+  return encodingParameters;
+};
+
+// parses http://draft.ortc.org/#rtcrtcpparameters*
+SDPUtils.parseRtcpParameters = function(mediaSection) {
+  var rtcpParameters = {};
+
+  var cname;
+  // Gets the first SSRC. Note that with RTX there might be multiple
+  // SSRCs.
+  var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+      .map(function(line) {
+        return SDPUtils.parseSsrcMedia(line);
+      })
+      .filter(function(obj) {
+        return obj.attribute === 'cname';
+      })[0];
+  if (remoteSsrc) {
+    rtcpParameters.cname = remoteSsrc.value;
+    rtcpParameters.ssrc = remoteSsrc.ssrc;
+  }
+
+  // Edge uses the compound attribute instead of reducedSize
+  // compound is !reducedSize
+  var rsize = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-rsize');
+  rtcpParameters.reducedSize = rsize.length > 0;
+  rtcpParameters.compound = rsize.length === 0;
+
+  // parses the rtcp-mux attrіbute.
+  // Note that Edge does not support unmuxed RTCP.
+  var mux = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-mux');
+  rtcpParameters.mux = mux.length > 0;
+
+  return rtcpParameters;
+};
+
+// parses either a=msid: or a=ssrc:... msid lines and returns
+// the id of the MediaStream and MediaStreamTrack.
+SDPUtils.parseMsid = function(mediaSection) {
+  var parts;
+  var spec = SDPUtils.matchPrefix(mediaSection, 'a=msid:');
+  if (spec.length === 1) {
+    parts = spec[0].substr(7).split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+  var planB = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'msid';
+  });
+  if (planB.length > 0) {
+    parts = planB[0].value.split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+};
+
+// Generate a session ID for SDP.
+// https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-20#section-5.2.1
+// recommends using a cryptographically random +ve 64-bit value
+// but right now this should be acceptable and within the right range
+SDPUtils.generateSessionId = function() {
+  return Math.random().toString().substr(2, 21);
+};
+
+// Write boilder plate for start of SDP
+// sessId argument is optional - if not supplied it will
+// be generated randomly
+// sessVersion is optional and defaults to 2
+SDPUtils.writeSessionBoilerplate = function(sessId, sessVer) {
+  var sessionId;
+  var version = sessVer !== undefined ? sessVer : 2;
+  if (sessId) {
+    sessionId = sessId;
+  } else {
+    sessionId = SDPUtils.generateSessionId();
+  }
+  // FIXME: sess-id should be an NTP timestamp.
+  return 'v=0\r\n' +
+      'o=thisisadapterortc ' + sessionId + ' ' + version + ' IN IP4 127.0.0.1\r\n' +
+      's=-\r\n' +
+      't=0 0\r\n';
+};
+
+SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+};
+
+// Gets the direction from the mediaSection or the sessionpart.
+SDPUtils.getDirection = function(mediaSection, sessionpart) {
+  // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
+  var lines = SDPUtils.splitLines(mediaSection);
+  for (var i = 0; i < lines.length; i++) {
+    switch (lines[i]) {
+      case 'a=sendrecv':
+      case 'a=sendonly':
+      case 'a=recvonly':
+      case 'a=inactive':
+        return lines[i].substr(2);
+      default:
+        // FIXME: What should happen here?
+    }
+  }
+  if (sessionpart) {
+    return SDPUtils.getDirection(sessionpart);
+  }
+  return 'sendrecv';
+};
+
+SDPUtils.getKind = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return mline[0].substr(2);
+};
+
+SDPUtils.isRejected = function(mediaSection) {
+  return mediaSection.split(' ', 2)[1] === '0';
+};
+
+SDPUtils.parseMLine = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return {
+    kind: mline[0].substr(2),
+    port: parseInt(mline[1], 10),
+    protocol: mline[2],
+    fmt: mline.slice(3).join(' ')
+  };
+};
+
+// Expose public methods.
+if (typeof module === 'object') {
+  module.exports = SDPUtils;
+}
+
+},{}],3:[function(require,module,exports){
+(function (global){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var adapterFactory = require('./adapter_factory.js');
+module.exports = adapterFactory({window: global.window});
+
+}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
+},{"./adapter_factory.js":4}],4:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var utils = require('./utils');
+// Shimming starts here.
+module.exports = function(dependencies, opts) {
+  var window = dependencies && dependencies.window;
+
+  var options = {
+    shimChrome: true,
+    shimFirefox: true,
+    shimEdge: true,
+    shimSafari: true,
+  };
+
+  for (var key in opts) {
+    if (hasOwnProperty.call(opts, key)) {
+      options[key] = opts[key];
+    }
+  }
+
+  // Utils.
+  var logging = utils.log;
+  var browserDetails = utils.detectBrowser(window);
+
+  // Export to the adapter global object visible in the browser.
+  var adapter = {
+    browserDetails: browserDetails,
+    extractVersion: utils.extractVersion,
+    disableLog: utils.disableLog,
+    disableWarnings: utils.disableWarnings
+  };
+
+  // Uncomment the line below if you want logging to occur, including logging
+  // for the switch statement below. Can also be turned on in the browser via
+  // adapter.disableLog(false), but then logging from the switch statement below
+  // will not appear.
+  // require('./utils').disableLog(false);
+
+  // Browser shims.
+  var chromeShim = require('./chrome/chrome_shim') || null;
+  var edgeShim = require('./edge/edge_shim') || null;
+  var firefoxShim = require('./firefox/firefox_shim') || null;
+  var safariShim = require('./safari/safari_shim') || null;
+  var commonShim = require('./common_shim') || null;
+
+  // Shim browser if found.
+  switch (browserDetails.browser) {
+    case 'chrome':
+      if (!chromeShim || !chromeShim.shimPeerConnection ||
+          !options.shimChrome) {
+        logging('Chrome shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      chromeShim.shimGetUserMedia(window);
+      chromeShim.shimMediaStream(window);
+      chromeShim.shimSourceObject(window);
+      chromeShim.shimPeerConnection(window);
+      chromeShim.shimOnTrack(window);
+      chromeShim.shimAddTrackRemoveTrack(window);
+      chromeShim.shimGetSendersWithDtmf(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'firefox':
+      if (!firefoxShim || !firefoxShim.shimPeerConnection ||
+          !options.shimFirefox) {
+        logging('Firefox shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming firefox.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = firefoxShim;
+      commonShim.shimCreateObjectURL(window);
+
+      firefoxShim.shimGetUserMedia(window);
+      firefoxShim.shimSourceObject(window);
+      firefoxShim.shimPeerConnection(window);
+      firefoxShim.shimOnTrack(window);
+      firefoxShim.shimRemoveStream(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'edge':
+      if (!edgeShim || !edgeShim.shimPeerConnection || !options.shimEdge) {
+        logging('MS edge shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming edge.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = edgeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      edgeShim.shimGetUserMedia(window);
+      edgeShim.shimPeerConnection(window);
+      edgeShim.shimReplaceTrack(window);
+
+      // the edge shim implements the full RTCIceCandidate object.
+      break;
+    case 'safari':
+      if (!safariShim || !options.shimSafari) {
+        logging('Safari shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming safari.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = safariShim;
+      commonShim.shimCreateObjectURL(window);
+
+      safariShim.shimRTCIceServerUrls(window);
+      safariShim.shimCallbacksAPI(window);
+      safariShim.shimLocalStreamsAPI(window);
+      safariShim.shimRemoteStreamsAPI(window);
+      safariShim.shimTrackEventTransceiver(window);
+      safariShim.shimGetUserMedia(window);
+      safariShim.shimCreateOfferLegacy(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+
+  return adapter;
+};
+
+},{"./chrome/chrome_shim":5,"./common_shim":7,"./edge/edge_shim":1,"./firefox/firefox_shim":8,"./safari/safari_shim":10,"./utils":11}],5:[function(require,module,exports){
+
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+var chromeShim = {
+  shimMediaStream: function(window) {
+    window.MediaStream = window.MediaStream || window.webkitMediaStream;
+  },
+
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+          }
+          this.addEventListener('track', this._ontrack = f);
+        }
+      });
+      var origSetRemoteDescription =
+          window.RTCPeerConnection.prototype.setRemoteDescription;
+      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
+        var pc = this;
+        if (!pc._ontrackpoly) {
+          pc._ontrackpoly = function(e) {
+            // onaddstream does not fire when a track is added to an existing
+            // stream. But stream.onaddtrack is implemented so we use that.
+            e.stream.addEventListener('addtrack', function(te) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === te.track.id;
+                });
+              } else {
+                receiver = {track: te.track};
+              }
+
+              var event = new Event('track');
+              event.track = te.track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+            e.stream.getTracks().forEach(function(track) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === track.id;
+                });
+              } else {
+                receiver = {track: track};
+              }
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+          };
+          pc.addEventListener('addstream', pc._ontrackpoly);
+        }
+        return origSetRemoteDescription.apply(pc, arguments);
+      };
+    }
+  },
+
+  shimGetSendersWithDtmf: function(window) {
+    // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        !('getSenders' in window.RTCPeerConnection.prototype) &&
+        'createDTMFSender' in window.RTCPeerConnection.prototype) {
+      var shimSenderWithDtmf = function(pc, track) {
+        return {
+          track: track,
+          get dtmf() {
+            if (this._dtmf === undefined) {
+              if (track.kind === 'audio') {
+                this._dtmf = pc.createDTMFSender(track);
+              } else {
+                this._dtmf = null;
+              }
+            }
+            return this._dtmf;
+          },
+          _pc: pc
+        };
+      };
+
+      // augment addTrack when getSenders is not available.
+      if (!window.RTCPeerConnection.prototype.getSenders) {
+        window.RTCPeerConnection.prototype.getSenders = function() {
+          this._senders = this._senders || [];
+          return this._senders.slice(); // return a copy of the internal state.
+        };
+        var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+        window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+          var pc = this;
+          var sender = origAddTrack.apply(pc, arguments);
+          if (!sender) {
+            sender = shimSenderWithDtmf(pc, track);
+            pc._senders.push(sender);
+          }
+          return sender;
+        };
+
+        var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+        window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+          var pc = this;
+          origRemoveTrack.apply(pc, arguments);
+          var idx = pc._senders.indexOf(sender);
+          if (idx !== -1) {
+            pc._senders.splice(idx, 1);
+          }
+        };
+      }
+      var origAddStream = window.RTCPeerConnection.prototype.addStream;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origAddStream.apply(pc, [stream]);
+        stream.getTracks().forEach(function(track) {
+          pc._senders.push(shimSenderWithDtmf(pc, track));
+        });
+      };
+
+      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origRemoveStream.apply(pc, [stream]);
+
+        stream.getTracks().forEach(function(track) {
+          var sender = pc._senders.find(function(s) {
+            return s.track === track;
+          });
+          if (sender) {
+            pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
+          }
+        });
+      };
+    } else if (typeof window === 'object' && window.RTCPeerConnection &&
+               'getSenders' in window.RTCPeerConnection.prototype &&
+               'createDTMFSender' in window.RTCPeerConnection.prototype &&
+               window.RTCRtpSender &&
+               !('dtmf' in window.RTCRtpSender.prototype)) {
+      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+      window.RTCPeerConnection.prototype.getSenders = function() {
+        var pc = this;
+        var senders = origGetSenders.apply(pc, []);
+        senders.forEach(function(sender) {
+          sender._pc = pc;
+        });
+        return senders;
+      };
+
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = this._pc.createDTMFSender(this.track);
+            } else {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    var URL = window && window.URL;
+
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this._srcObject;
+          },
+          set: function(stream) {
+            var self = this;
+            // Use _srcObject as a private property for this shim
+            this._srcObject = stream;
+            if (this.src) {
+              URL.revokeObjectURL(this.src);
+            }
+
+            if (!stream) {
+              this.src = '';
+              return undefined;
+            }
+            this.src = URL.createObjectURL(stream);
+            // We need to recreate the blob url when a track is added or
+            // removed. Doing it manually since we want to avoid a recursion.
+            stream.addEventListener('addtrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+            stream.addEventListener('removetrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+          }
+        });
+      }
+    }
+  },
+
+  shimAddTrackRemoveTrack: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+    // shim addTrack and removeTrack.
+    if (window.RTCPeerConnection.prototype.addTrack &&
+        browserDetails.version >= 64) {
+      return;
+    }
+
+    // also shim pc.getLocalStreams when addTrack is shimmed
+    // to return the original streams.
+    var origGetLocalStreams = window.RTCPeerConnection.prototype
+        .getLocalStreams;
+    window.RTCPeerConnection.prototype.getLocalStreams = function() {
+      var self = this;
+      var nativeStreams = origGetLocalStreams.apply(this);
+      self._reverseStreams = self._reverseStreams || {};
+      return nativeStreams.map(function(stream) {
+        return self._reverseStreams[stream.id];
+      });
+    };
+
+    var origAddStream = window.RTCPeerConnection.prototype.addStream;
+    window.RTCPeerConnection.prototype.addStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      stream.getTracks().forEach(function(track) {
+        var alreadyExists = pc.getSenders().find(function(s) {
+          return s.track === track;
+        });
+        if (alreadyExists) {
+          throw new DOMException('Track already exists.',
+              'InvalidAccessError');
+        }
+      });
+      // Add identity mapping for consistency with addTrack.
+      // Unless this is being used with a stream from addTrack.
+      if (!pc._reverseStreams[stream.id]) {
+        var newStream = new window.MediaStream(stream.getTracks());
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        stream = newStream;
+      }
+      origAddStream.apply(pc, [stream]);
+    };
+
+    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
+      delete pc._reverseStreams[(pc._streams[stream.id] ?
+          pc._streams[stream.id].id : stream.id)];
+      delete pc._streams[stream.id];
+    };
+
+    window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      var streams = [].slice.call(arguments, 1);
+      if (streams.length !== 1 ||
+          !streams[0].getTracks().find(function(t) {
+            return t === track;
+          })) {
+        // this is not fully correct but all we can manage without
+        // [[associated MediaStreams]] internal slot.
+        throw new DOMException(
+          'The adapter.js addTrack polyfill only supports a single ' +
+          ' stream which is associated with the specified track.',
+          'NotSupportedError');
+      }
+
+      var alreadyExists = pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+            'InvalidAccessError');
+      }
+
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+      var oldStream = pc._streams[stream.id];
+      if (oldStream) {
+        // this is using odd Chrome behaviour, use with caution:
+        // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
+        // Note: we rely on the high-level addTrack/dtmf shim to
+        // create the sender with a dtmf sender.
+        oldStream.addTrack(track);
+
+        // Trigger ONN async.
+        Promise.resolve().then(function() {
+          pc.dispatchEvent(new Event('negotiationneeded'));
+        });
+      } else {
+        var newStream = new window.MediaStream([track]);
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        pc.addStream(newStream);
+      }
+      return pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+    };
+
+    // replace the internal stream id with the external one and
+    // vice versa.
+    function replaceInternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
+            externalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    function replaceExternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
+            internalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    ['createOffer', 'createAnswer'].forEach(function(method) {
+      var nativeMethod = window.RTCPeerConnection.prototype[method];
+      window.RTCPeerConnection.prototype[method] = function() {
+        var pc = this;
+        var args = arguments;
+        var isLegacyCall = arguments.length &&
+            typeof arguments[0] === 'function';
+        if (isLegacyCall) {
+          return nativeMethod.apply(pc, [
+            function(description) {
+              var desc = replaceInternalStreamId(pc, description);
+              args[0].apply(null, [desc]);
+            },
+            function(err) {
+              if (args[1]) {
+                args[1].apply(null, err);
+              }
+            }, arguments[2]
+          ]);
+        }
+        return nativeMethod.apply(pc, arguments)
+        .then(function(description) {
+          return replaceInternalStreamId(pc, description);
+        });
+      };
+    });
+
+    var origSetLocalDescription =
+        window.RTCPeerConnection.prototype.setLocalDescription;
+    window.RTCPeerConnection.prototype.setLocalDescription = function() {
+      var pc = this;
+      if (!arguments.length || !arguments[0].type) {
+        return origSetLocalDescription.apply(pc, arguments);
+      }
+      arguments[0] = replaceExternalStreamId(pc, arguments[0]);
+      return origSetLocalDescription.apply(pc, arguments);
+    };
+
+    // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
+
+    var origLocalDescription = Object.getOwnPropertyDescriptor(
+        window.RTCPeerConnection.prototype, 'localDescription');
+    Object.defineProperty(window.RTCPeerConnection.prototype,
+        'localDescription', {
+          get: function() {
+            var pc = this;
+            var description = origLocalDescription.get.apply(this);
+            if (description.type === '') {
+              return description;
+            }
+            return replaceInternalStreamId(pc, description);
+          }
+        });
+
+    window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      // We can not yet check for sender instanceof RTCRtpSender
+      // since we shim RTPSender. So we check if sender._pc is set.
+      if (!sender._pc) {
+        throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
+            'does not implement interface RTCRtpSender.', 'TypeError');
+      }
+      var isLocal = sender._pc === pc;
+      if (!isLocal) {
+        throw new DOMException('Sender was not created by this connection.',
+            'InvalidAccessError');
+      }
+
+      // Search for the native stream the senders track belongs to.
+      pc._streams = pc._streams || {};
+      var stream;
+      Object.keys(pc._streams).forEach(function(streamid) {
+        var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
+          return sender.track === track;
+        });
+        if (hasTrack) {
+          stream = pc._streams[streamid];
+        }
+      });
+
+      if (stream) {
+        if (stream.getTracks().length === 1) {
+          // if this is the last track of the stream, remove the stream. This
+          // takes care of any shimmed _senders.
+          pc.removeStream(pc._reverseStreams[stream.id]);
+        } else {
+          // relying on the same odd chrome behaviour as above.
+          stream.removeTrack(sender.track);
+        }
+        pc.dispatchEvent(new Event('negotiationneeded'));
+      }
+    };
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        // Translate iceTransportPolicy to iceTransports,
+        // see https://code.google.com/p/webrtc/issues/detail?id=4869
+        // this was fixed in M56 along with unprefixing RTCPeerConnection.
+        logging('PeerConnection');
+        if (pcConfig && pcConfig.iceTransportPolicy) {
+          pcConfig.iceTransports = pcConfig.iceTransportPolicy;
+        }
+
+        return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.webkitRTCPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      if (window.webkitRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.webkitRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+    } else {
+      // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+      var OrigPeerConnection = window.RTCPeerConnection;
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (pcConfig && pcConfig.iceServers) {
+          var newIceServers = [];
+          for (var i = 0; i < pcConfig.iceServers.length; i++) {
+            var server = pcConfig.iceServers[i];
+            if (!server.hasOwnProperty('urls') &&
+                server.hasOwnProperty('url')) {
+              utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+              server = JSON.parse(JSON.stringify(server));
+              server.urls = server.url;
+              newIceServers.push(server);
+            } else {
+              newIceServers.push(pcConfig.iceServers[i]);
+            }
+          }
+          pcConfig.iceServers = newIceServers;
+        }
+        return new OrigPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+
+    var origGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(selector,
+        successCallback, errorCallback) {
+      var self = this;
+      var args = arguments;
+
+      // If selector is a function then we are in the old style stats so just
+      // pass back the original getStats format to avoid breaking old users.
+      if (arguments.length > 0 && typeof selector === 'function') {
+        return origGetStats.apply(this, arguments);
+      }
+
+      // When spec-style getStats is supported, return those when called with
+      // either no arguments or the selector argument is null.
+      if (origGetStats.length === 0 && (arguments.length === 0 ||
+          typeof arguments[0] !== 'function')) {
+        return origGetStats.apply(this, []);
+      }
+
+      var fixChromeStats_ = function(response) {
+        var standardReport = {};
+        var reports = response.result();
+        reports.forEach(function(report) {
+          var standardStats = {
+            id: report.id,
+            timestamp: report.timestamp,
+            type: {
+              localcandidate: 'local-candidate',
+              remotecandidate: 'remote-candidate'
+            }[report.type] || report.type
+          };
+          report.names().forEach(function(name) {
+            standardStats[name] = report.stat(name);
+          });
+          standardReport[standardStats.id] = standardStats;
+        });
+
+        return standardReport;
+      };
+
+      // shim getStats with maplike support
+      var makeMapStats = function(stats) {
+        return new Map(Object.keys(stats).map(function(key) {
+          return [key, stats[key]];
+        }));
+      };
+
+      if (arguments.length >= 2) {
+        var successCallbackWrapper_ = function(response) {
+          args[1](makeMapStats(fixChromeStats_(response)));
+        };
+
+        return origGetStats.apply(this, [successCallbackWrapper_,
+          arguments[0]]);
+      }
+
+      // promise-support
+      return new Promise(function(resolve, reject) {
+        origGetStats.apply(self, [
+          function(response) {
+            resolve(makeMapStats(fixChromeStats_(response)));
+          }, reject]);
+      }).then(successCallback, errorCallback);
+    };
+
+    // add promise support -- natively available in Chrome 51
+    if (browserDetails.version < 51) {
+      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+          .forEach(function(method) {
+            var nativeMethod = window.RTCPeerConnection.prototype[method];
+            window.RTCPeerConnection.prototype[method] = function() {
+              var args = arguments;
+              var self = this;
+              var promise = new Promise(function(resolve, reject) {
+                nativeMethod.apply(self, [args[0], resolve, reject]);
+              });
+              if (args.length < 2) {
+                return promise;
+              }
+              return promise.then(function() {
+                args[1].apply(null, []);
+              },
+              function(err) {
+                if (args.length >= 3) {
+                  args[2].apply(null, [err]);
+                }
+              });
+            };
+          });
+    }
+
+    // promise support for createOffer and createAnswer. Available (without
+    // bugs) since M52: crbug/619289
+    if (browserDetails.version < 52) {
+      ['createOffer', 'createAnswer'].forEach(function(method) {
+        var nativeMethod = window.RTCPeerConnection.prototype[method];
+        window.RTCPeerConnection.prototype[method] = function() {
+          var self = this;
+          if (arguments.length < 1 || (arguments.length === 1 &&
+              typeof arguments[0] === 'object')) {
+            var opts = arguments.length === 1 ? arguments[0] : undefined;
+            return new Promise(function(resolve, reject) {
+              nativeMethod.apply(self, [resolve, reject, opts]);
+            });
+          }
+          return nativeMethod.apply(this, arguments);
+        };
+      });
+    }
+
+    // shim implicit creation of RTCSessionDescription/RTCIceCandidate
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+  }
+};
+
+
+// Expose public methods.
+module.exports = {
+  shimMediaStream: chromeShim.shimMediaStream,
+  shimOnTrack: chromeShim.shimOnTrack,
+  shimAddTrackRemoveTrack: chromeShim.shimAddTrackRemoveTrack,
+  shimGetSendersWithDtmf: chromeShim.shimGetSendersWithDtmf,
+  shimSourceObject: chromeShim.shimSourceObject,
+  shimPeerConnection: chromeShim.shimPeerConnection,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils.js":11,"./getusermedia":6}],6:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+
+  var constraintsToChrome_ = function(c) {
+    if (typeof c !== 'object' || c.mandatory || c.optional) {
+      return c;
+    }
+    var cc = {};
+    Object.keys(c).forEach(function(key) {
+      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+        return;
+      }
+      var r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
+      if (r.exact !== undefined && typeof r.exact === 'number') {
+        r.min = r.max = r.exact;
+      }
+      var oldname_ = function(prefix, name) {
+        if (prefix) {
+          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+        }
+        return (name === 'deviceId') ? 'sourceId' : name;
+      };
+      if (r.ideal !== undefined) {
+        cc.optional = cc.optional || [];
+        var oc = {};
+        if (typeof r.ideal === 'number') {
+          oc[oldname_('min', key)] = r.ideal;
+          cc.optional.push(oc);
+          oc = {};
+          oc[oldname_('max', key)] = r.ideal;
+          cc.optional.push(oc);
+        } else {
+          oc[oldname_('', key)] = r.ideal;
+          cc.optional.push(oc);
+        }
+      }
+      if (r.exact !== undefined && typeof r.exact !== 'number') {
+        cc.mandatory = cc.mandatory || {};
+        cc.mandatory[oldname_('', key)] = r.exact;
+      } else {
+        ['min', 'max'].forEach(function(mix) {
+          if (r[mix] !== undefined) {
+            cc.mandatory = cc.mandatory || {};
+            cc.mandatory[oldname_(mix, key)] = r[mix];
+          }
+        });
+      }
+    });
+    if (c.advanced) {
+      cc.optional = (cc.optional || []).concat(c.advanced);
+    }
+    return cc;
+  };
+
+  var shimConstraints_ = function(constraints, func) {
+    if (browserDetails.version >= 61) {
+      return func(constraints);
+    }
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (constraints && typeof constraints.audio === 'object') {
+      var remap = function(obj, a, b) {
+        if (a in obj && !(b in obj)) {
+          obj[b] = obj[a];
+          delete obj[a];
+        }
+      };
+      constraints = JSON.parse(JSON.stringify(constraints));
+      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
+      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
+      constraints.audio = constraintsToChrome_(constraints.audio);
+    }
+    if (constraints && typeof constraints.video === 'object') {
+      // Shim facingMode for mobile & surface pro.
+      var face = constraints.video.facingMode;
+      face = face && ((typeof face === 'object') ? face : {ideal: face});
+      var getSupportedFacingModeLies = browserDetails.version < 66;
+
+      if ((face && (face.exact === 'user' || face.exact === 'environment' ||
+                    face.ideal === 'user' || face.ideal === 'environment')) &&
+          !(navigator.mediaDevices.getSupportedConstraints &&
+            navigator.mediaDevices.getSupportedConstraints().facingMode &&
+            !getSupportedFacingModeLies)) {
+        delete constraints.video.facingMode;
+        var matches;
+        if (face.exact === 'environment' || face.ideal === 'environment') {
+          matches = ['back', 'rear'];
+        } else if (face.exact === 'user' || face.ideal === 'user') {
+          matches = ['front'];
+        }
+        if (matches) {
+          // Look for matches in label, or use last cam for back (typical).
+          return navigator.mediaDevices.enumerateDevices()
+          .then(function(devices) {
+            devices = devices.filter(function(d) {
+              return d.kind === 'videoinput';
+            });
+            var dev = devices.find(function(d) {
+              return matches.some(function(match) {
+                return d.label.toLowerCase().indexOf(match) !== -1;
+              });
+            });
+            if (!dev && devices.length && matches.indexOf('back') !== -1) {
+              dev = devices[devices.length - 1]; // more likely the back cam
+            }
+            if (dev) {
+              constraints.video.deviceId = face.exact ? {exact: dev.deviceId} :
+                                                        {ideal: dev.deviceId};
+            }
+            constraints.video = constraintsToChrome_(constraints.video);
+            logging('chrome: ' + JSON.stringify(constraints));
+            return func(constraints);
+          });
+        }
+      }
+      constraints.video = constraintsToChrome_(constraints.video);
+    }
+    logging('chrome: ' + JSON.stringify(constraints));
+    return func(constraints);
+  };
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        PermissionDeniedError: 'NotAllowedError',
+        InvalidStateError: 'NotReadableError',
+        DevicesNotFoundError: 'NotFoundError',
+        ConstraintNotSatisfiedError: 'OverconstrainedError',
+        TrackStartError: 'NotReadableError',
+        MediaDeviceFailedDueToShutdown: 'NotReadableError',
+        MediaDeviceKillSwitchOn: 'NotReadableError'
+      }[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraintName,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    shimConstraints_(constraints, function(c) {
+      navigator.webkitGetUserMedia(c, onSuccess, function(e) {
+        if (onError) {
+          onError(shimError_(e));
+        }
+      });
+    });
+  };
+
+  navigator.getUserMedia = getUserMedia_;
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      navigator.getUserMedia(constraints, resolve, reject);
+    });
+  };
+
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {
+      getUserMedia: getUserMediaPromise_,
+      enumerateDevices: function() {
+        return new Promise(function(resolve) {
+          var kinds = {audio: 'audioinput', video: 'videoinput'};
+          return window.MediaStreamTrack.getSources(function(devices) {
+            resolve(devices.map(function(device) {
+              return {label: device.label,
+                kind: kinds[device.kind],
+                deviceId: device.id,
+                groupId: ''};
+            }));
+          });
+        });
+      },
+      getSupportedConstraints: function() {
+        return {
+          deviceId: true, echoCancellation: true, facingMode: true,
+          frameRate: true, height: true, width: true
+        };
+      }
+    };
+  }
+
+  // A shim for getUserMedia method on the mediaDevices object.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (!navigator.mediaDevices.getUserMedia) {
+    navigator.mediaDevices.getUserMedia = function(constraints) {
+      return getUserMediaPromise_(constraints);
+    };
+  } else {
+    // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
+    // function which returns a Promise, it does not accept spec-style
+    // constraints.
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(cs) {
+      return shimConstraints_(cs, function(c) {
+        return origGetUserMedia(c).then(function(stream) {
+          if (c.audio && !stream.getAudioTracks().length ||
+              c.video && !stream.getVideoTracks().length) {
+            stream.getTracks().forEach(function(track) {
+              track.stop();
+            });
+            throw new DOMException('', 'NotFoundError');
+          }
+          return stream;
+        }, function(e) {
+          return Promise.reject(shimError_(e));
+        });
+      });
+    };
+  }
+
+  // Dummy devicechange event methods.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
+    navigator.mediaDevices.addEventListener = function() {
+      logging('Dummy mediaDevices.addEventListener called.');
+    };
+  }
+  if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
+    navigator.mediaDevices.removeEventListener = function() {
+      logging('Dummy mediaDevices.removeEventListener called.');
+    };
+  }
+};
+
+},{"../utils.js":11}],7:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+var utils = require('./utils');
+
+// Wraps the peerconnection event eventNameToWrap in a function
+// which returns the modified event object.
+function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  var proto = window.RTCPeerConnection.prototype;
+  var nativeAddEventListener = proto.addEventListener;
+  proto.addEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap) {
+      return nativeAddEventListener.apply(this, arguments);
+    }
+    var wrappedCallback = function(e) {
+      cb(wrapper(e));
+    };
+    this._eventMap = this._eventMap || {};
+    this._eventMap[cb] = wrappedCallback;
+    return nativeAddEventListener.apply(this, [nativeEventName,
+      wrappedCallback]);
+  };
+
+  var nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap
+        || !this._eventMap[cb]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    var unwrappedCb = this._eventMap[cb];
+    delete this._eventMap[cb];
+    return nativeRemoveEventListener.apply(this, [nativeEventName,
+      unwrappedCb]);
+  };
+
+  Object.defineProperty(proto, 'on' + eventNameToWrap, {
+    get: function() {
+      return this['_on' + eventNameToWrap];
+    },
+    set: function(cb) {
+      if (this['_on' + eventNameToWrap]) {
+        this.removeEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap]);
+        delete this['_on' + eventNameToWrap];
+      }
+      if (cb) {
+        this.addEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap] = cb);
+      }
+    }
+  });
+}
+
+module.exports = {
+  shimRTCIceCandidate: function(window) {
+    // foundation is arbitrarily chosen as an indicator for full support for
+    // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
+    if (window.RTCIceCandidate && 'foundation' in
+        window.RTCIceCandidate.prototype) {
+      return;
+    }
+
+    var NativeRTCIceCandidate = window.RTCIceCandidate;
+    window.RTCIceCandidate = function(args) {
+      // Remove the a= which shouldn't be part of the candidate string.
+      if (typeof args === 'object' && args.candidate &&
+          args.candidate.indexOf('a=') === 0) {
+        args = JSON.parse(JSON.stringify(args));
+        args.candidate = args.candidate.substr(2);
+      }
+
+      // Augment the native candidate with the parsed fields.
+      var nativeCandidate = new NativeRTCIceCandidate(args);
+      var parsedCandidate = SDPUtils.parseCandidate(args.candidate);
+      var augmentedCandidate = Object.assign(nativeCandidate,
+          parsedCandidate);
+
+      // Add a serializer that does not serialize the extra attributes.
+      augmentedCandidate.toJSON = function() {
+        return {
+          candidate: augmentedCandidate.candidate,
+          sdpMid: augmentedCandidate.sdpMid,
+          sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
+          usernameFragment: augmentedCandidate.usernameFragment,
+        };
+      };
+      return augmentedCandidate;
+    };
+
+    // Hook up the augmented candidate in onicecandidate and
+    // addEventListener('icecandidate', ...)
+    wrapPeerConnectionEvent(window, 'icecandidate', function(e) {
+      if (e.candidate) {
+        Object.defineProperty(e, 'candidate', {
+          value: new window.RTCIceCandidate(e.candidate),
+          writable: 'false'
+        });
+      }
+      return e;
+    });
+  },
+
+  // shimCreateObjectURL must be called before shimSourceObject to avoid loop.
+
+  shimCreateObjectURL: function(window) {
+    var URL = window && window.URL;
+
+    if (!(typeof window === 'object' && window.HTMLMediaElement &&
+          'srcObject' in window.HTMLMediaElement.prototype &&
+        URL.createObjectURL && URL.revokeObjectURL)) {
+      // Only shim CreateObjectURL using srcObject if srcObject exists.
+      return undefined;
+    }
+
+    var nativeCreateObjectURL = URL.createObjectURL.bind(URL);
+    var nativeRevokeObjectURL = URL.revokeObjectURL.bind(URL);
+    var streams = new Map(), newId = 0;
+
+    URL.createObjectURL = function(stream) {
+      if ('getTracks' in stream) {
+        var url = 'polyblob:' + (++newId);
+        streams.set(url, stream);
+        utils.deprecated('URL.createObjectURL(stream)',
+            'elem.srcObject = stream');
+        return url;
+      }
+      return nativeCreateObjectURL(stream);
+    };
+    URL.revokeObjectURL = function(url) {
+      nativeRevokeObjectURL(url);
+      streams.delete(url);
+    };
+
+    var dsc = Object.getOwnPropertyDescriptor(window.HTMLMediaElement.prototype,
+                                              'src');
+    Object.defineProperty(window.HTMLMediaElement.prototype, 'src', {
+      get: function() {
+        return dsc.get.apply(this);
+      },
+      set: function(url) {
+        this.srcObject = streams.get(url) || null;
+        return dsc.set.apply(this, [url]);
+      }
+    });
+
+    var nativeSetAttribute = window.HTMLMediaElement.prototype.setAttribute;
+    window.HTMLMediaElement.prototype.setAttribute = function() {
+      if (arguments.length === 2 &&
+          ('' + arguments[0]).toLowerCase() === 'src') {
+        this.srcObject = streams.get(arguments[1]) || null;
+      }
+      return nativeSetAttribute.apply(this, arguments);
+    };
+  }
+};
+
+},{"./utils":11,"sdp":2}],8:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+
+var firefoxShim = {
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+            this.removeEventListener('addstream', this._ontrackpoly);
+          }
+          this.addEventListener('track', this._ontrack = f);
+          this.addEventListener('addstream', this._ontrackpoly = function(e) {
+            e.stream.getTracks().forEach(function(track) {
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = {track: track};
+              event.transceiver = {receiver: event.receiver};
+              event.streams = [e.stream];
+              this.dispatchEvent(event);
+            }.bind(this));
+          }.bind(this));
+        }
+      });
+    }
+    if (typeof window === 'object' && window.RTCTrackEvent &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        !('transceiver' in window.RTCTrackEvent.prototype)) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this.mozSrcObject;
+          },
+          set: function(stream) {
+            this.mozSrcObject = stream;
+          }
+        });
+      }
+    }
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (typeof window !== 'object' || !(window.RTCPeerConnection ||
+        window.mozRTCPeerConnection)) {
+      return; // probably media.peerconnection.enabled=false in about:config
+    }
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (browserDetails.version < 38) {
+          // .urls is not supported in FF < 38.
+          // create RTCIceServers with a single url.
+          if (pcConfig && pcConfig.iceServers) {
+            var newIceServers = [];
+            for (var i = 0; i < pcConfig.iceServers.length; i++) {
+              var server = pcConfig.iceServers[i];
+              if (server.hasOwnProperty('urls')) {
+                for (var j = 0; j < server.urls.length; j++) {
+                  var newServer = {
+                    url: server.urls[j]
+                  };
+                  if (server.urls[j].indexOf('turn') === 0) {
+                    newServer.username = server.username;
+                    newServer.credential = server.credential;
+                  }
+                  newIceServers.push(newServer);
+                }
+              } else {
+                newIceServers.push(pcConfig.iceServers[i]);
+              }
+            }
+            pcConfig.iceServers = newIceServers;
+          }
+        }
+        return new window.mozRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.mozRTCPeerConnection.prototype;
+
+      // wrap static methods. Currently just generateCertificate.
+      if (window.mozRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.mozRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+
+      window.RTCSessionDescription = window.mozRTCSessionDescription;
+      window.RTCIceCandidate = window.mozRTCIceCandidate;
+    }
+
+    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+
+    // shim getStats with maplike support
+    var makeMapStats = function(stats) {
+      var map = new Map();
+      Object.keys(stats).forEach(function(key) {
+        map.set(key, stats[key]);
+        map[key] = stats[key];
+      });
+      return map;
+    };
+
+    var modernStatsTypes = {
+      inboundrtp: 'inbound-rtp',
+      outboundrtp: 'outbound-rtp',
+      candidatepair: 'candidate-pair',
+      localcandidate: 'local-candidate',
+      remotecandidate: 'remote-candidate'
+    };
+
+    var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(
+      selector,
+      onSucc,
+      onErr
+    ) {
+      return nativeGetStats.apply(this, [selector || null])
+        .then(function(stats) {
+          if (browserDetails.version < 48) {
+            stats = makeMapStats(stats);
+          }
+          if (browserDetails.version < 53 && !onSucc) {
+            // Shim only promise getStats with spec-hyphens in type names
+            // Leave callback version alone; misc old uses of forEach before Map
+            try {
+              stats.forEach(function(stat) {
+                stat.type = modernStatsTypes[stat.type] || stat.type;
+              });
+            } catch (e) {
+              if (e.name !== 'TypeError') {
+                throw e;
+              }
+              // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
+              stats.forEach(function(stat, i) {
+                stats.set(i, Object.assign({}, stat, {
+                  type: modernStatsTypes[stat.type] || stat.type
+                }));
+              });
+            }
+          }
+          return stats;
+        })
+        .then(onSucc, onErr);
+    };
+  },
+
+  shimRemoveStream: function(window) {
+    if (!window.RTCPeerConnection ||
+        'removeStream' in window.RTCPeerConnection.prototype) {
+      return;
+    }
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      utils.deprecated('removeStream', 'removeTrack');
+      this.getSenders().forEach(function(sender) {
+        if (sender.track && stream.getTracks().indexOf(sender.track) !== -1) {
+          pc.removeTrack(sender);
+        }
+      });
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimOnTrack: firefoxShim.shimOnTrack,
+  shimSourceObject: firefoxShim.shimSourceObject,
+  shimPeerConnection: firefoxShim.shimPeerConnection,
+  shimRemoveStream: firefoxShim.shimRemoveStream,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils":11,"./getusermedia":9}],9:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+  var MediaStreamTrack = window && window.MediaStreamTrack;
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        InternalError: 'NotReadableError',
+        NotSupportedError: 'TypeError',
+        PermissionDeniedError: 'NotAllowedError',
+        SecurityError: 'NotAllowedError'
+      }[e.name] || e.name,
+      message: {
+        'The operation is insecure.': 'The request is not allowed by the ' +
+        'user agent or the platform in the current context.'
+      }[e.message] || e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  // getUserMedia constraints shim.
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    var constraintsToFF37_ = function(c) {
+      if (typeof c !== 'object' || c.require) {
+        return c;
+      }
+      var require = [];
+      Object.keys(c).forEach(function(key) {
+        if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+          return;
+        }
+        var r = c[key] = (typeof c[key] === 'object') ?
+            c[key] : {ideal: c[key]};
+        if (r.min !== undefined ||
+            r.max !== undefined || r.exact !== undefined) {
+          require.push(key);
+        }
+        if (r.exact !== undefined) {
+          if (typeof r.exact === 'number') {
+            r. min = r.max = r.exact;
+          } else {
+            c[key] = r.exact;
+          }
+          delete r.exact;
+        }
+        if (r.ideal !== undefined) {
+          c.advanced = c.advanced || [];
+          var oc = {};
+          if (typeof r.ideal === 'number') {
+            oc[key] = {min: r.ideal, max: r.ideal};
+          } else {
+            oc[key] = r.ideal;
+          }
+          c.advanced.push(oc);
+          delete r.ideal;
+          if (!Object.keys(r).length) {
+            delete c[key];
+          }
+        }
+      });
+      if (require.length) {
+        c.require = require;
+      }
+      return c;
+    };
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (browserDetails.version < 38) {
+      logging('spec: ' + JSON.stringify(constraints));
+      if (constraints.audio) {
+        constraints.audio = constraintsToFF37_(constraints.audio);
+      }
+      if (constraints.video) {
+        constraints.video = constraintsToFF37_(constraints.video);
+      }
+      logging('ff37: ' + JSON.stringify(constraints));
+    }
+    return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
+      onError(shimError_(e));
+    });
+  };
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      getUserMedia_(constraints, resolve, reject);
+    });
+  };
+
+  // Shim for mediaDevices on older versions.
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
+      addEventListener: function() { },
+      removeEventListener: function() { }
+    };
+  }
+  navigator.mediaDevices.enumerateDevices =
+      navigator.mediaDevices.enumerateDevices || function() {
+        return new Promise(function(resolve) {
+          var infos = [
+            {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
+            {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
+          ];
+          resolve(infos);
+        });
+      };
+
+  if (browserDetails.version < 41) {
+    // Work around http://bugzil.la/1169665
+    var orgEnumerateDevices =
+        navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
+    navigator.mediaDevices.enumerateDevices = function() {
+      return orgEnumerateDevices().then(undefined, function(e) {
+        if (e.name === 'NotFoundError') {
+          return [];
+        }
+        throw e;
+      });
+    };
+  }
+  if (browserDetails.version < 49) {
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      return origGetUserMedia(c).then(function(stream) {
+        // Work around https://bugzil.la/802326
+        if (c.audio && !stream.getAudioTracks().length ||
+            c.video && !stream.getVideoTracks().length) {
+          stream.getTracks().forEach(function(track) {
+            track.stop();
+          });
+          throw new DOMException('The object can not be found here.',
+                                 'NotFoundError');
+        }
+        return stream;
+      }, function(e) {
+        return Promise.reject(shimError_(e));
+      });
+    };
+  }
+  if (!(browserDetails.version > 55 &&
+      'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
+    var remap = function(obj, a, b) {
+      if (a in obj && !(b in obj)) {
+        obj[b] = obj[a];
+        delete obj[a];
+      }
+    };
+
+    var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      if (typeof c === 'object' && typeof c.audio === 'object') {
+        c = JSON.parse(JSON.stringify(c));
+        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
+        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
+      }
+      return nativeGetUserMedia(c);
+    };
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
+      var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
+      MediaStreamTrack.prototype.getSettings = function() {
+        var obj = nativeGetSettings.apply(this, arguments);
+        remap(obj, 'mozAutoGainControl', 'autoGainControl');
+        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
+        return obj;
+      };
+    }
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
+      var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
+      MediaStreamTrack.prototype.applyConstraints = function(c) {
+        if (this.kind === 'audio' && typeof c === 'object') {
+          c = JSON.parse(JSON.stringify(c));
+          remap(c, 'autoGainControl', 'mozAutoGainControl');
+          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
+        }
+        return nativeApplyConstraints.apply(this, [c]);
+      };
+    }
+  }
+  navigator.getUserMedia = function(constraints, onSuccess, onError) {
+    if (browserDetails.version < 44) {
+      return getUserMedia_(constraints, onSuccess, onError);
+    }
+    // Replace Firefox 44+'s deprecation warning with unprefixed version.
+    utils.deprecated('navigator.getUserMedia',
+        'navigator.mediaDevices.getUserMedia');
+    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
+  };
+};
+
+},{"../utils":11}],10:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+'use strict';
+var utils = require('../utils');
+
+var safariShim = {
+  // TODO: DrAlex, should be here, double check against LayoutTests
+
+  // TODO: once the back-end for the mac port is done, add.
+  // TODO: check for webkitGTK+
+  // shimPeerConnection: function() { },
+
+  shimLocalStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getLocalStreams = function() {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        return this._localStreams;
+      };
+    }
+    if (!('getStreamById' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getStreamById = function(id) {
+        var result = null;
+        if (this._localStreams) {
+          this._localStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        if (this._remoteStreams) {
+          this._remoteStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        return result;
+      };
+    }
+    if (!('addStream' in window.RTCPeerConnection.prototype)) {
+      var _addTrack = window.RTCPeerConnection.prototype.addTrack;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        if (this._localStreams.indexOf(stream) === -1) {
+          this._localStreams.push(stream);
+        }
+        var self = this;
+        stream.getTracks().forEach(function(track) {
+          _addTrack.call(self, track, stream);
+        });
+      };
+
+      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+        if (stream) {
+          if (!this._localStreams) {
+            this._localStreams = [stream];
+          } else if (this._localStreams.indexOf(stream) === -1) {
+            this._localStreams.push(stream);
+          }
+        }
+        return _addTrack.call(this, track, stream);
+      };
+    }
+    if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        var index = this._localStreams.indexOf(stream);
+        if (index === -1) {
+          return;
+        }
+        this._localStreams.splice(index, 1);
+        var self = this;
+        var tracks = stream.getTracks();
+        this.getSenders().forEach(function(sender) {
+          if (tracks.indexOf(sender.track) !== -1) {
+            self.removeTrack(sender);
+          }
+        });
+      };
+    }
+  },
+  shimRemoteStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getRemoteStreams = function() {
+        return this._remoteStreams ? this._remoteStreams : [];
+      };
+    }
+    if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
+        get: function() {
+          return this._onaddstream;
+        },
+        set: function(f) {
+          if (this._onaddstream) {
+            this.removeEventListener('addstream', this._onaddstream);
+            this.removeEventListener('track', this._onaddstreampoly);
+          }
+          this.addEventListener('addstream', this._onaddstream = f);
+          this.addEventListener('track', this._onaddstreampoly = function(e) {
+            var stream = e.streams[0];
+            if (!this._remoteStreams) {
+              this._remoteStreams = [];
+            }
+            if (this._remoteStreams.indexOf(stream) >= 0) {
+              return;
+            }
+            this._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = e.streams[0];
+            this.dispatchEvent(event);
+          }.bind(this));
+        }
+      });
+    }
+  },
+  shimCallbacksAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    var prototype = window.RTCPeerConnection.prototype;
+    var createOffer = prototype.createOffer;
+    var createAnswer = prototype.createAnswer;
+    var setLocalDescription = prototype.setLocalDescription;
+    var setRemoteDescription = prototype.setRemoteDescription;
+    var addIceCandidate = prototype.addIceCandidate;
+
+    prototype.createOffer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createOffer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    prototype.createAnswer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createAnswer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    var withCallback = function(description, successCallback, failureCallback) {
+      var promise = setLocalDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setLocalDescription = withCallback;
+
+    withCallback = function(description, successCallback, failureCallback) {
+      var promise = setRemoteDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setRemoteDescription = withCallback;
+
+    withCallback = function(candidate, successCallback, failureCallback) {
+      var promise = addIceCandidate.apply(this, [candidate]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.addIceCandidate = withCallback;
+  },
+  shimGetUserMedia: function(window) {
+    var navigator = window && window.navigator;
+
+    if (!navigator.getUserMedia) {
+      if (navigator.webkitGetUserMedia) {
+        navigator.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
+      } else if (navigator.mediaDevices &&
+          navigator.mediaDevices.getUserMedia) {
+        navigator.getUserMedia = function(constraints, cb, errcb) {
+          navigator.mediaDevices.getUserMedia(constraints)
+          .then(cb, errcb);
+        }.bind(navigator);
+      }
+    }
+  },
+  shimRTCIceServerUrls: function(window) {
+    // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+    var OrigPeerConnection = window.RTCPeerConnection;
+    window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+      if (pcConfig && pcConfig.iceServers) {
+        var newIceServers = [];
+        for (var i = 0; i < pcConfig.iceServers.length; i++) {
+          var server = pcConfig.iceServers[i];
+          if (!server.hasOwnProperty('urls') &&
+              server.hasOwnProperty('url')) {
+            utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+            server = JSON.parse(JSON.stringify(server));
+            server.urls = server.url;
+            delete server.url;
+            newIceServers.push(server);
+          } else {
+            newIceServers.push(pcConfig.iceServers[i]);
+          }
+        }
+        pcConfig.iceServers = newIceServers;
+      }
+      return new OrigPeerConnection(pcConfig, pcConstraints);
+    };
+    window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+    // wrap static methods. Currently just generateCertificate.
+    if ('generateCertificate' in window.RTCPeerConnection) {
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+  },
+  shimTrackEventTransceiver: function(window) {
+    // Add event.transceiver member over deprecated event.receiver
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        // can't check 'transceiver' in window.RTCTrackEvent.prototype, as it is
+        // defined for some reason even when window.RTCTransceiver is not.
+        !window.RTCTransceiver) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimCreateOfferLegacy: function(window) {
+    var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+    window.RTCPeerConnection.prototype.createOffer = function(offerOptions) {
+      var pc = this;
+      if (offerOptions) {
+        var audioTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'audio';
+        });
+        if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
+          if (audioTransceiver.direction === 'sendrecv') {
+            audioTransceiver.setDirection('sendonly');
+          } else if (audioTransceiver.direction === 'recvonly') {
+            audioTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveAudio === true &&
+            !audioTransceiver) {
+          pc.addTransceiver('audio');
+        }
+
+        var videoTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'video';
+        });
+        if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
+          if (videoTransceiver.direction === 'sendrecv') {
+            videoTransceiver.setDirection('sendonly');
+          } else if (videoTransceiver.direction === 'recvonly') {
+            videoTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveVideo === true &&
+            !videoTransceiver) {
+          pc.addTransceiver('video');
+        }
+      }
+      return origCreateOffer.apply(pc, arguments);
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimCallbacksAPI: safariShim.shimCallbacksAPI,
+  shimLocalStreamsAPI: safariShim.shimLocalStreamsAPI,
+  shimRemoteStreamsAPI: safariShim.shimRemoteStreamsAPI,
+  shimGetUserMedia: safariShim.shimGetUserMedia,
+  shimRTCIceServerUrls: safariShim.shimRTCIceServerUrls,
+  shimTrackEventTransceiver: safariShim.shimTrackEventTransceiver,
+  shimCreateOfferLegacy: safariShim.shimCreateOfferLegacy
+  // TODO
+  // shimPeerConnection: safariShim.shimPeerConnection
+};
+
+},{"../utils":11}],11:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var logDisabled_ = true;
+var deprecationWarnings_ = true;
+
+// Utility methods.
+var utils = {
+  disableLog: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    logDisabled_ = bool;
+    return (bool) ? 'adapter.js logging disabled' :
+        'adapter.js logging enabled';
+  },
+
+  /**
+   * Disable or enable deprecation warnings
+   * @param {!boolean} bool set to true to disable warnings.
+   */
+  disableWarnings: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    deprecationWarnings_ = !bool;
+    return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
+  },
+
+  log: function() {
+    if (typeof window === 'object') {
+      if (logDisabled_) {
+        return;
+      }
+      if (typeof console !== 'undefined' && typeof console.log === 'function') {
+        console.log.apply(console, arguments);
+      }
+    }
+  },
+
+  /**
+   * Shows a deprecation warning suggesting the modern and spec-compatible API.
+   */
+  deprecated: function(oldMethod, newMethod) {
+    if (!deprecationWarnings_) {
+      return;
+    }
+    console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
+        ' instead.');
+  },
+
+  /**
+   * Extract browser version out of the provided user agent string.
+   *
+   * @param {!string} uastring userAgent string.
+   * @param {!string} expr Regular expression used as match criteria.
+   * @param {!number} pos position in the version string to be returned.
+   * @return {!number} browser version.
+   */
+  extractVersion: function(uastring, expr, pos) {
+    var match = uastring.match(expr);
+    return match && match.length >= pos && parseInt(match[pos], 10);
+  },
+
+  /**
+   * Browser detector.
+   *
+   * @return {object} result containing browser and version
+   *     properties.
+   */
+  detectBrowser: function(window) {
+    var navigator = window && window.navigator;
+
+    // Returned result object.
+    var result = {};
+    result.browser = null;
+    result.version = null;
+
+    // Fail early if it's not a browser
+    if (typeof window === 'undefined' || !window.navigator) {
+      result.browser = 'Not a browser.';
+      return result;
+    }
+
+    // Firefox.
+    if (navigator.mozGetUserMedia) {
+      result.browser = 'firefox';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Firefox\/(\d+)\./, 1);
+    } else if (navigator.webkitGetUserMedia) {
+      // Chrome, Chromium, Webview, Opera, all use the chrome shim for now
+      if (window.webkitRTCPeerConnection) {
+        result.browser = 'chrome';
+        result.version = this.extractVersion(navigator.userAgent,
+          /Chrom(e|ium)\/(\d+)\./, 2);
+      } else { // Safari (in an unpublished version) or unknown webkit-based.
+        if (navigator.userAgent.match(/Version\/(\d+).(\d+)/)) {
+          result.browser = 'safari';
+          result.version = this.extractVersion(navigator.userAgent,
+            /AppleWebKit\/(\d+)\./, 1);
+        } else { // unknown webkit-based browser.
+          result.browser = 'Unsupported webkit-based browser ' +
+              'with GUM support but no WebRTC support.';
+          return result;
+        }
+      }
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) { // Edge.
+      result.browser = 'edge';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Edge\/(\d+).(\d+)$/, 2);
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) {
+        // Safari, with webkitGetUserMedia removed.
+      result.browser = 'safari';
+      result.version = this.extractVersion(navigator.userAgent,
+          /AppleWebKit\/(\d+)\./, 1);
+    } else { // Default fallthrough: not supported.
+      result.browser = 'Not a supported browser.';
+      return result;
+    }
+
+    return result;
+  },
+
+};
+
+// Export.
+module.exports = {
+  log: utils.log,
+  deprecated: utils.deprecated,
+  disableLog: utils.disableLog,
+  disableWarnings: utils.disableWarnings,
+  extractVersion: utils.extractVersion,
+  shimCreateObjectURL: utils.shimCreateObjectURL,
+  detectBrowser: utils.detectBrowser.bind(utils)
+};
+
+},{}]},{},[3])(3)
+});

+ 2794 - 0
support/client/lib/vwf/view/webrtc/dist/adapter_no_edge_no_global.js

@@ -0,0 +1,2794 @@
+(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+
+},{}],2:[function(require,module,exports){
+ /* eslint-env node */
+'use strict';
+
+// SDP helpers.
+var SDPUtils = {};
+
+// Generate an alphanumeric identifier for cname or mids.
+// TODO: use UUIDs instead? https://gist.github.com/jed/982883
+SDPUtils.generateIdentifier = function() {
+  return Math.random().toString(36).substr(2, 10);
+};
+
+// The RTCP CNAME used by all peerconnections from the same JS.
+SDPUtils.localCName = SDPUtils.generateIdentifier();
+
+// Splits SDP into lines, dealing with both CRLF and LF.
+SDPUtils.splitLines = function(blob) {
+  return blob.trim().split('\n').map(function(line) {
+    return line.trim();
+  });
+};
+// Splits SDP into sessionpart and mediasections. Ensures CRLF.
+SDPUtils.splitSections = function(blob) {
+  var parts = blob.split('\nm=');
+  return parts.map(function(part, index) {
+    return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
+  });
+};
+
+// Returns lines that start with a certain prefix.
+SDPUtils.matchPrefix = function(blob, prefix) {
+  return SDPUtils.splitLines(blob).filter(function(line) {
+    return line.indexOf(prefix) === 0;
+  });
+};
+
+// Parses an ICE candidate line. Sample input:
+// candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8
+// rport 55996"
+SDPUtils.parseCandidate = function(line) {
+  var parts;
+  // Parse both variants.
+  if (line.indexOf('a=candidate:') === 0) {
+    parts = line.substring(12).split(' ');
+  } else {
+    parts = line.substring(10).split(' ');
+  }
+
+  var candidate = {
+    foundation: parts[0],
+    component: parseInt(parts[1], 10),
+    protocol: parts[2].toLowerCase(),
+    priority: parseInt(parts[3], 10),
+    ip: parts[4],
+    port: parseInt(parts[5], 10),
+    // skip parts[6] == 'typ'
+    type: parts[7]
+  };
+
+  for (var i = 8; i < parts.length; i += 2) {
+    switch (parts[i]) {
+      case 'raddr':
+        candidate.relatedAddress = parts[i + 1];
+        break;
+      case 'rport':
+        candidate.relatedPort = parseInt(parts[i + 1], 10);
+        break;
+      case 'tcptype':
+        candidate.tcpType = parts[i + 1];
+        break;
+      case 'ufrag':
+        candidate.ufrag = parts[i + 1]; // for backward compability.
+        candidate.usernameFragment = parts[i + 1];
+        break;
+      default: // extension handling, in particular ufrag
+        candidate[parts[i]] = parts[i + 1];
+        break;
+    }
+  }
+  return candidate;
+};
+
+// Translates a candidate object into SDP candidate attribute.
+SDPUtils.writeCandidate = function(candidate) {
+  var sdp = [];
+  sdp.push(candidate.foundation);
+  sdp.push(candidate.component);
+  sdp.push(candidate.protocol.toUpperCase());
+  sdp.push(candidate.priority);
+  sdp.push(candidate.ip);
+  sdp.push(candidate.port);
+
+  var type = candidate.type;
+  sdp.push('typ');
+  sdp.push(type);
+  if (type !== 'host' && candidate.relatedAddress &&
+      candidate.relatedPort) {
+    sdp.push('raddr');
+    sdp.push(candidate.relatedAddress); // was: relAddr
+    sdp.push('rport');
+    sdp.push(candidate.relatedPort); // was: relPort
+  }
+  if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
+    sdp.push('tcptype');
+    sdp.push(candidate.tcpType);
+  }
+  if (candidate.ufrag) {
+    sdp.push('ufrag');
+    sdp.push(candidate.ufrag);
+  }
+  return 'candidate:' + sdp.join(' ');
+};
+
+// Parses an ice-options line, returns an array of option tags.
+// a=ice-options:foo bar
+SDPUtils.parseIceOptions = function(line) {
+  return line.substr(14).split(' ');
+}
+
+// Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
+// a=rtpmap:111 opus/48000/2
+SDPUtils.parseRtpMap = function(line) {
+  var parts = line.substr(9).split(' ');
+  var parsed = {
+    payloadType: parseInt(parts.shift(), 10) // was: id
+  };
+
+  parts = parts[0].split('/');
+
+  parsed.name = parts[0];
+  parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
+  // was: channels
+  parsed.numChannels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
+  return parsed;
+};
+
+// Generate an a=rtpmap line from RTCRtpCodecCapability or
+// RTCRtpCodecParameters.
+SDPUtils.writeRtpMap = function(codec) {
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
+      (codec.numChannels !== 1 ? '/' + codec.numChannels : '') + '\r\n';
+};
+
+// Parses an a=extmap line (headerextension from RFC 5285). Sample input:
+// a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
+// a=extmap:2/sendonly urn:ietf:params:rtp-hdrext:toffset
+SDPUtils.parseExtmap = function(line) {
+  var parts = line.substr(9).split(' ');
+  return {
+    id: parseInt(parts[0], 10),
+    direction: parts[0].indexOf('/') > 0 ? parts[0].split('/')[1] : 'sendrecv',
+    uri: parts[1]
+  };
+};
+
+// Generates a=extmap line from RTCRtpHeaderExtensionParameters or
+// RTCRtpHeaderExtension.
+SDPUtils.writeExtmap = function(headerExtension) {
+  return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
+      (headerExtension.direction && headerExtension.direction !== 'sendrecv'
+          ? '/' + headerExtension.direction
+          : '') +
+      ' ' + headerExtension.uri + '\r\n';
+};
+
+// Parses an ftmp line, returns dictionary. Sample input:
+// a=fmtp:96 vbr=on;cng=on
+// Also deals with vbr=on; cng=on
+SDPUtils.parseFmtp = function(line) {
+  var parsed = {};
+  var kv;
+  var parts = line.substr(line.indexOf(' ') + 1).split(';');
+  for (var j = 0; j < parts.length; j++) {
+    kv = parts[j].trim().split('=');
+    parsed[kv[0].trim()] = kv[1];
+  }
+  return parsed;
+};
+
+// Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeFmtp = function(codec) {
+  var line = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.parameters && Object.keys(codec.parameters).length) {
+    var params = [];
+    Object.keys(codec.parameters).forEach(function(param) {
+      params.push(param + '=' + codec.parameters[param]);
+    });
+    line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
+  }
+  return line;
+};
+
+// Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
+// a=rtcp-fb:98 nack rpsi
+SDPUtils.parseRtcpFb = function(line) {
+  var parts = line.substr(line.indexOf(' ') + 1).split(' ');
+  return {
+    type: parts.shift(),
+    parameter: parts.join(' ')
+  };
+};
+// Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeRtcpFb = function(codec) {
+  var lines = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
+    // FIXME: special handling for trr-int?
+    codec.rtcpFeedback.forEach(function(fb) {
+      lines += 'a=rtcp-fb:' + pt + ' ' + fb.type +
+      (fb.parameter && fb.parameter.length ? ' ' + fb.parameter : '') +
+          '\r\n';
+    });
+  }
+  return lines;
+};
+
+// Parses an RFC 5576 ssrc media attribute. Sample input:
+// a=ssrc:3735928559 cname:something
+SDPUtils.parseSsrcMedia = function(line) {
+  var sp = line.indexOf(' ');
+  var parts = {
+    ssrc: parseInt(line.substr(7, sp - 7), 10)
+  };
+  var colon = line.indexOf(':', sp);
+  if (colon > -1) {
+    parts.attribute = line.substr(sp + 1, colon - sp - 1);
+    parts.value = line.substr(colon + 1);
+  } else {
+    parts.attribute = line.substr(sp + 1);
+  }
+  return parts;
+};
+
+// Extracts the MID (RFC 5888) from a media section.
+// returns the MID or undefined if no mid line was found.
+SDPUtils.getMid = function(mediaSection) {
+  var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0];
+  if (mid) {
+    return mid.substr(6);
+  }
+}
+
+SDPUtils.parseFingerprint = function(line) {
+  var parts = line.substr(14).split(' ');
+  return {
+    algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
+    value: parts[1]
+  };
+};
+
+// Extracts DTLS parameters from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the fingerprint line as input. See also getIceParameters.
+SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.matchPrefix(mediaSection + sessionpart,
+      'a=fingerprint:');
+  // Note: a=setup line is ignored since we use the 'auto' role.
+  // Note2: 'algorithm' is not case sensitive except in Edge.
+  return {
+    role: 'auto',
+    fingerprints: lines.map(SDPUtils.parseFingerprint)
+  };
+};
+
+// Serializes DTLS parameters to SDP.
+SDPUtils.writeDtlsParameters = function(params, setupType) {
+  var sdp = 'a=setup:' + setupType + '\r\n';
+  params.fingerprints.forEach(function(fp) {
+    sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
+  });
+  return sdp;
+};
+// Parses ICE information from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the ice-ufrag and ice-pwd lines as input.
+SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  // Search in session part, too.
+  lines = lines.concat(SDPUtils.splitLines(sessionpart));
+  var iceParameters = {
+    usernameFragment: lines.filter(function(line) {
+      return line.indexOf('a=ice-ufrag:') === 0;
+    })[0].substr(12),
+    password: lines.filter(function(line) {
+      return line.indexOf('a=ice-pwd:') === 0;
+    })[0].substr(10)
+  };
+  return iceParameters;
+};
+
+// Serializes ICE parameters to SDP.
+SDPUtils.writeIceParameters = function(params) {
+  return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
+      'a=ice-pwd:' + params.password + '\r\n';
+};
+
+// Parses the SDP media section and returns RTCRtpParameters.
+SDPUtils.parseRtpParameters = function(mediaSection) {
+  var description = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: [],
+    rtcp: []
+  };
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
+    var pt = mline[i];
+    var rtpmapline = SDPUtils.matchPrefix(
+        mediaSection, 'a=rtpmap:' + pt + ' ')[0];
+    if (rtpmapline) {
+      var codec = SDPUtils.parseRtpMap(rtpmapline);
+      var fmtps = SDPUtils.matchPrefix(
+          mediaSection, 'a=fmtp:' + pt + ' ');
+      // Only the first a=fmtp:<pt> is considered.
+      codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
+      codec.rtcpFeedback = SDPUtils.matchPrefix(
+          mediaSection, 'a=rtcp-fb:' + pt + ' ')
+        .map(SDPUtils.parseRtcpFb);
+      description.codecs.push(codec);
+      // parse FEC mechanisms from rtpmap lines.
+      switch (codec.name.toUpperCase()) {
+        case 'RED':
+        case 'ULPFEC':
+          description.fecMechanisms.push(codec.name.toUpperCase());
+          break;
+        default: // only RED and ULPFEC are recognized as FEC mechanisms.
+          break;
+      }
+    }
+  }
+  SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
+    description.headerExtensions.push(SDPUtils.parseExtmap(line));
+  });
+  // FIXME: parse rtcp.
+  return description;
+};
+
+// Generates parts of the SDP media section describing the capabilities /
+// parameters.
+SDPUtils.writeRtpDescription = function(kind, caps) {
+  var sdp = '';
+
+  // Build the mline.
+  sdp += 'm=' + kind + ' ';
+  sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
+  sdp += ' UDP/TLS/RTP/SAVPF ';
+  sdp += caps.codecs.map(function(codec) {
+    if (codec.preferredPayloadType !== undefined) {
+      return codec.preferredPayloadType;
+    }
+    return codec.payloadType;
+  }).join(' ') + '\r\n';
+
+  sdp += 'c=IN IP4 0.0.0.0\r\n';
+  sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';
+
+  // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
+  caps.codecs.forEach(function(codec) {
+    sdp += SDPUtils.writeRtpMap(codec);
+    sdp += SDPUtils.writeFmtp(codec);
+    sdp += SDPUtils.writeRtcpFb(codec);
+  });
+  var maxptime = 0;
+  caps.codecs.forEach(function(codec) {
+    if (codec.maxptime > maxptime) {
+      maxptime = codec.maxptime;
+    }
+  });
+  if (maxptime > 0) {
+    sdp += 'a=maxptime:' + maxptime + '\r\n';
+  }
+  sdp += 'a=rtcp-mux\r\n';
+
+  caps.headerExtensions.forEach(function(extension) {
+    sdp += SDPUtils.writeExtmap(extension);
+  });
+  // FIXME: write fecMechanisms.
+  return sdp;
+};
+
+// Parses the SDP media section and returns an array of
+// RTCRtpEncodingParameters.
+SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
+  var encodingParameters = [];
+  var description = SDPUtils.parseRtpParameters(mediaSection);
+  var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
+  var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;
+
+  // filter a=ssrc:... cname:, ignore PlanB-msid
+  var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'cname';
+  });
+  var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
+  var secondarySsrc;
+
+  var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
+  .map(function(line) {
+    var parts = line.split(' ');
+    parts.shift();
+    return parts.map(function(part) {
+      return parseInt(part, 10);
+    });
+  });
+  if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
+    secondarySsrc = flows[0][1];
+  }
+
+  description.codecs.forEach(function(codec) {
+    if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
+      var encParam = {
+        ssrc: primarySsrc,
+        codecPayloadType: parseInt(codec.parameters.apt, 10),
+        rtx: {
+          ssrc: secondarySsrc
+        }
+      };
+      encodingParameters.push(encParam);
+      if (hasRed) {
+        encParam = JSON.parse(JSON.stringify(encParam));
+        encParam.fec = {
+          ssrc: secondarySsrc,
+          mechanism: hasUlpfec ? 'red+ulpfec' : 'red'
+        };
+        encodingParameters.push(encParam);
+      }
+    }
+  });
+  if (encodingParameters.length === 0 && primarySsrc) {
+    encodingParameters.push({
+      ssrc: primarySsrc
+    });
+  }
+
+  // we support both b=AS and b=TIAS but interpret AS as TIAS.
+  var bandwidth = SDPUtils.matchPrefix(mediaSection, 'b=');
+  if (bandwidth.length) {
+    if (bandwidth[0].indexOf('b=TIAS:') === 0) {
+      bandwidth = parseInt(bandwidth[0].substr(7), 10);
+    } else if (bandwidth[0].indexOf('b=AS:') === 0) {
+      // use formula from JSEP to convert b=AS to TIAS value.
+      bandwidth = parseInt(bandwidth[0].substr(5), 10) * 1000 * 0.95
+          - (50 * 40 * 8);
+    } else {
+      bandwidth = undefined;
+    }
+    encodingParameters.forEach(function(params) {
+      params.maxBitrate = bandwidth;
+    });
+  }
+  return encodingParameters;
+};
+
+// parses http://draft.ortc.org/#rtcrtcpparameters*
+SDPUtils.parseRtcpParameters = function(mediaSection) {
+  var rtcpParameters = {};
+
+  var cname;
+  // Gets the first SSRC. Note that with RTX there might be multiple
+  // SSRCs.
+  var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+      .map(function(line) {
+        return SDPUtils.parseSsrcMedia(line);
+      })
+      .filter(function(obj) {
+        return obj.attribute === 'cname';
+      })[0];
+  if (remoteSsrc) {
+    rtcpParameters.cname = remoteSsrc.value;
+    rtcpParameters.ssrc = remoteSsrc.ssrc;
+  }
+
+  // Edge uses the compound attribute instead of reducedSize
+  // compound is !reducedSize
+  var rsize = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-rsize');
+  rtcpParameters.reducedSize = rsize.length > 0;
+  rtcpParameters.compound = rsize.length === 0;
+
+  // parses the rtcp-mux attrіbute.
+  // Note that Edge does not support unmuxed RTCP.
+  var mux = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-mux');
+  rtcpParameters.mux = mux.length > 0;
+
+  return rtcpParameters;
+};
+
+// parses either a=msid: or a=ssrc:... msid lines and returns
+// the id of the MediaStream and MediaStreamTrack.
+SDPUtils.parseMsid = function(mediaSection) {
+  var parts;
+  var spec = SDPUtils.matchPrefix(mediaSection, 'a=msid:');
+  if (spec.length === 1) {
+    parts = spec[0].substr(7).split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+  var planB = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'msid';
+  });
+  if (planB.length > 0) {
+    parts = planB[0].value.split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+};
+
+// Generate a session ID for SDP.
+// https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-20#section-5.2.1
+// recommends using a cryptographically random +ve 64-bit value
+// but right now this should be acceptable and within the right range
+SDPUtils.generateSessionId = function() {
+  return Math.random().toString().substr(2, 21);
+};
+
+// Write boilder plate for start of SDP
+// sessId argument is optional - if not supplied it will
+// be generated randomly
+// sessVersion is optional and defaults to 2
+SDPUtils.writeSessionBoilerplate = function(sessId, sessVer) {
+  var sessionId;
+  var version = sessVer !== undefined ? sessVer : 2;
+  if (sessId) {
+    sessionId = sessId;
+  } else {
+    sessionId = SDPUtils.generateSessionId();
+  }
+  // FIXME: sess-id should be an NTP timestamp.
+  return 'v=0\r\n' +
+      'o=thisisadapterortc ' + sessionId + ' ' + version + ' IN IP4 127.0.0.1\r\n' +
+      's=-\r\n' +
+      't=0 0\r\n';
+};
+
+SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+};
+
+// Gets the direction from the mediaSection or the sessionpart.
+SDPUtils.getDirection = function(mediaSection, sessionpart) {
+  // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
+  var lines = SDPUtils.splitLines(mediaSection);
+  for (var i = 0; i < lines.length; i++) {
+    switch (lines[i]) {
+      case 'a=sendrecv':
+      case 'a=sendonly':
+      case 'a=recvonly':
+      case 'a=inactive':
+        return lines[i].substr(2);
+      default:
+        // FIXME: What should happen here?
+    }
+  }
+  if (sessionpart) {
+    return SDPUtils.getDirection(sessionpart);
+  }
+  return 'sendrecv';
+};
+
+SDPUtils.getKind = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return mline[0].substr(2);
+};
+
+SDPUtils.isRejected = function(mediaSection) {
+  return mediaSection.split(' ', 2)[1] === '0';
+};
+
+SDPUtils.parseMLine = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return {
+    kind: mline[0].substr(2),
+    port: parseInt(mline[1], 10),
+    protocol: mline[2],
+    fmt: mline.slice(3).join(' ')
+  };
+};
+
+// Expose public methods.
+if (typeof module === 'object') {
+  module.exports = SDPUtils;
+}
+
+},{}],3:[function(require,module,exports){
+(function (global){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var adapterFactory = require('./adapter_factory.js');
+module.exports = adapterFactory({window: global.window});
+
+}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
+},{"./adapter_factory.js":4}],4:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var utils = require('./utils');
+// Shimming starts here.
+module.exports = function(dependencies, opts) {
+  var window = dependencies && dependencies.window;
+
+  var options = {
+    shimChrome: true,
+    shimFirefox: true,
+    shimEdge: true,
+    shimSafari: true,
+  };
+
+  for (var key in opts) {
+    if (hasOwnProperty.call(opts, key)) {
+      options[key] = opts[key];
+    }
+  }
+
+  // Utils.
+  var logging = utils.log;
+  var browserDetails = utils.detectBrowser(window);
+
+  // Export to the adapter global object visible in the browser.
+  var adapter = {
+    browserDetails: browserDetails,
+    extractVersion: utils.extractVersion,
+    disableLog: utils.disableLog,
+    disableWarnings: utils.disableWarnings
+  };
+
+  // Uncomment the line below if you want logging to occur, including logging
+  // for the switch statement below. Can also be turned on in the browser via
+  // adapter.disableLog(false), but then logging from the switch statement below
+  // will not appear.
+  // require('./utils').disableLog(false);
+
+  // Browser shims.
+  var chromeShim = require('./chrome/chrome_shim') || null;
+  var edgeShim = require('./edge/edge_shim') || null;
+  var firefoxShim = require('./firefox/firefox_shim') || null;
+  var safariShim = require('./safari/safari_shim') || null;
+  var commonShim = require('./common_shim') || null;
+
+  // Shim browser if found.
+  switch (browserDetails.browser) {
+    case 'chrome':
+      if (!chromeShim || !chromeShim.shimPeerConnection ||
+          !options.shimChrome) {
+        logging('Chrome shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      chromeShim.shimGetUserMedia(window);
+      chromeShim.shimMediaStream(window);
+      chromeShim.shimSourceObject(window);
+      chromeShim.shimPeerConnection(window);
+      chromeShim.shimOnTrack(window);
+      chromeShim.shimAddTrackRemoveTrack(window);
+      chromeShim.shimGetSendersWithDtmf(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'firefox':
+      if (!firefoxShim || !firefoxShim.shimPeerConnection ||
+          !options.shimFirefox) {
+        logging('Firefox shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming firefox.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = firefoxShim;
+      commonShim.shimCreateObjectURL(window);
+
+      firefoxShim.shimGetUserMedia(window);
+      firefoxShim.shimSourceObject(window);
+      firefoxShim.shimPeerConnection(window);
+      firefoxShim.shimOnTrack(window);
+      firefoxShim.shimRemoveStream(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'edge':
+      if (!edgeShim || !edgeShim.shimPeerConnection || !options.shimEdge) {
+        logging('MS edge shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming edge.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = edgeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      edgeShim.shimGetUserMedia(window);
+      edgeShim.shimPeerConnection(window);
+      edgeShim.shimReplaceTrack(window);
+
+      // the edge shim implements the full RTCIceCandidate object.
+      break;
+    case 'safari':
+      if (!safariShim || !options.shimSafari) {
+        logging('Safari shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming safari.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = safariShim;
+      commonShim.shimCreateObjectURL(window);
+
+      safariShim.shimRTCIceServerUrls(window);
+      safariShim.shimCallbacksAPI(window);
+      safariShim.shimLocalStreamsAPI(window);
+      safariShim.shimRemoteStreamsAPI(window);
+      safariShim.shimTrackEventTransceiver(window);
+      safariShim.shimGetUserMedia(window);
+      safariShim.shimCreateOfferLegacy(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+
+  return adapter;
+};
+
+},{"./chrome/chrome_shim":5,"./common_shim":7,"./edge/edge_shim":1,"./firefox/firefox_shim":8,"./safari/safari_shim":10,"./utils":11}],5:[function(require,module,exports){
+
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+var chromeShim = {
+  shimMediaStream: function(window) {
+    window.MediaStream = window.MediaStream || window.webkitMediaStream;
+  },
+
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+          }
+          this.addEventListener('track', this._ontrack = f);
+        }
+      });
+      var origSetRemoteDescription =
+          window.RTCPeerConnection.prototype.setRemoteDescription;
+      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
+        var pc = this;
+        if (!pc._ontrackpoly) {
+          pc._ontrackpoly = function(e) {
+            // onaddstream does not fire when a track is added to an existing
+            // stream. But stream.onaddtrack is implemented so we use that.
+            e.stream.addEventListener('addtrack', function(te) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === te.track.id;
+                });
+              } else {
+                receiver = {track: te.track};
+              }
+
+              var event = new Event('track');
+              event.track = te.track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+            e.stream.getTracks().forEach(function(track) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === track.id;
+                });
+              } else {
+                receiver = {track: track};
+              }
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+          };
+          pc.addEventListener('addstream', pc._ontrackpoly);
+        }
+        return origSetRemoteDescription.apply(pc, arguments);
+      };
+    }
+  },
+
+  shimGetSendersWithDtmf: function(window) {
+    // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        !('getSenders' in window.RTCPeerConnection.prototype) &&
+        'createDTMFSender' in window.RTCPeerConnection.prototype) {
+      var shimSenderWithDtmf = function(pc, track) {
+        return {
+          track: track,
+          get dtmf() {
+            if (this._dtmf === undefined) {
+              if (track.kind === 'audio') {
+                this._dtmf = pc.createDTMFSender(track);
+              } else {
+                this._dtmf = null;
+              }
+            }
+            return this._dtmf;
+          },
+          _pc: pc
+        };
+      };
+
+      // augment addTrack when getSenders is not available.
+      if (!window.RTCPeerConnection.prototype.getSenders) {
+        window.RTCPeerConnection.prototype.getSenders = function() {
+          this._senders = this._senders || [];
+          return this._senders.slice(); // return a copy of the internal state.
+        };
+        var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+        window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+          var pc = this;
+          var sender = origAddTrack.apply(pc, arguments);
+          if (!sender) {
+            sender = shimSenderWithDtmf(pc, track);
+            pc._senders.push(sender);
+          }
+          return sender;
+        };
+
+        var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+        window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+          var pc = this;
+          origRemoveTrack.apply(pc, arguments);
+          var idx = pc._senders.indexOf(sender);
+          if (idx !== -1) {
+            pc._senders.splice(idx, 1);
+          }
+        };
+      }
+      var origAddStream = window.RTCPeerConnection.prototype.addStream;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origAddStream.apply(pc, [stream]);
+        stream.getTracks().forEach(function(track) {
+          pc._senders.push(shimSenderWithDtmf(pc, track));
+        });
+      };
+
+      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origRemoveStream.apply(pc, [stream]);
+
+        stream.getTracks().forEach(function(track) {
+          var sender = pc._senders.find(function(s) {
+            return s.track === track;
+          });
+          if (sender) {
+            pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
+          }
+        });
+      };
+    } else if (typeof window === 'object' && window.RTCPeerConnection &&
+               'getSenders' in window.RTCPeerConnection.prototype &&
+               'createDTMFSender' in window.RTCPeerConnection.prototype &&
+               window.RTCRtpSender &&
+               !('dtmf' in window.RTCRtpSender.prototype)) {
+      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+      window.RTCPeerConnection.prototype.getSenders = function() {
+        var pc = this;
+        var senders = origGetSenders.apply(pc, []);
+        senders.forEach(function(sender) {
+          sender._pc = pc;
+        });
+        return senders;
+      };
+
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = this._pc.createDTMFSender(this.track);
+            } else {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    var URL = window && window.URL;
+
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this._srcObject;
+          },
+          set: function(stream) {
+            var self = this;
+            // Use _srcObject as a private property for this shim
+            this._srcObject = stream;
+            if (this.src) {
+              URL.revokeObjectURL(this.src);
+            }
+
+            if (!stream) {
+              this.src = '';
+              return undefined;
+            }
+            this.src = URL.createObjectURL(stream);
+            // We need to recreate the blob url when a track is added or
+            // removed. Doing it manually since we want to avoid a recursion.
+            stream.addEventListener('addtrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+            stream.addEventListener('removetrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+          }
+        });
+      }
+    }
+  },
+
+  shimAddTrackRemoveTrack: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+    // shim addTrack and removeTrack.
+    if (window.RTCPeerConnection.prototype.addTrack &&
+        browserDetails.version >= 64) {
+      return;
+    }
+
+    // also shim pc.getLocalStreams when addTrack is shimmed
+    // to return the original streams.
+    var origGetLocalStreams = window.RTCPeerConnection.prototype
+        .getLocalStreams;
+    window.RTCPeerConnection.prototype.getLocalStreams = function() {
+      var self = this;
+      var nativeStreams = origGetLocalStreams.apply(this);
+      self._reverseStreams = self._reverseStreams || {};
+      return nativeStreams.map(function(stream) {
+        return self._reverseStreams[stream.id];
+      });
+    };
+
+    var origAddStream = window.RTCPeerConnection.prototype.addStream;
+    window.RTCPeerConnection.prototype.addStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      stream.getTracks().forEach(function(track) {
+        var alreadyExists = pc.getSenders().find(function(s) {
+          return s.track === track;
+        });
+        if (alreadyExists) {
+          throw new DOMException('Track already exists.',
+              'InvalidAccessError');
+        }
+      });
+      // Add identity mapping for consistency with addTrack.
+      // Unless this is being used with a stream from addTrack.
+      if (!pc._reverseStreams[stream.id]) {
+        var newStream = new window.MediaStream(stream.getTracks());
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        stream = newStream;
+      }
+      origAddStream.apply(pc, [stream]);
+    };
+
+    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
+      delete pc._reverseStreams[(pc._streams[stream.id] ?
+          pc._streams[stream.id].id : stream.id)];
+      delete pc._streams[stream.id];
+    };
+
+    window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      var streams = [].slice.call(arguments, 1);
+      if (streams.length !== 1 ||
+          !streams[0].getTracks().find(function(t) {
+            return t === track;
+          })) {
+        // this is not fully correct but all we can manage without
+        // [[associated MediaStreams]] internal slot.
+        throw new DOMException(
+          'The adapter.js addTrack polyfill only supports a single ' +
+          ' stream which is associated with the specified track.',
+          'NotSupportedError');
+      }
+
+      var alreadyExists = pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+            'InvalidAccessError');
+      }
+
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+      var oldStream = pc._streams[stream.id];
+      if (oldStream) {
+        // this is using odd Chrome behaviour, use with caution:
+        // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
+        // Note: we rely on the high-level addTrack/dtmf shim to
+        // create the sender with a dtmf sender.
+        oldStream.addTrack(track);
+
+        // Trigger ONN async.
+        Promise.resolve().then(function() {
+          pc.dispatchEvent(new Event('negotiationneeded'));
+        });
+      } else {
+        var newStream = new window.MediaStream([track]);
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        pc.addStream(newStream);
+      }
+      return pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+    };
+
+    // replace the internal stream id with the external one and
+    // vice versa.
+    function replaceInternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
+            externalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    function replaceExternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
+            internalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    ['createOffer', 'createAnswer'].forEach(function(method) {
+      var nativeMethod = window.RTCPeerConnection.prototype[method];
+      window.RTCPeerConnection.prototype[method] = function() {
+        var pc = this;
+        var args = arguments;
+        var isLegacyCall = arguments.length &&
+            typeof arguments[0] === 'function';
+        if (isLegacyCall) {
+          return nativeMethod.apply(pc, [
+            function(description) {
+              var desc = replaceInternalStreamId(pc, description);
+              args[0].apply(null, [desc]);
+            },
+            function(err) {
+              if (args[1]) {
+                args[1].apply(null, err);
+              }
+            }, arguments[2]
+          ]);
+        }
+        return nativeMethod.apply(pc, arguments)
+        .then(function(description) {
+          return replaceInternalStreamId(pc, description);
+        });
+      };
+    });
+
+    var origSetLocalDescription =
+        window.RTCPeerConnection.prototype.setLocalDescription;
+    window.RTCPeerConnection.prototype.setLocalDescription = function() {
+      var pc = this;
+      if (!arguments.length || !arguments[0].type) {
+        return origSetLocalDescription.apply(pc, arguments);
+      }
+      arguments[0] = replaceExternalStreamId(pc, arguments[0]);
+      return origSetLocalDescription.apply(pc, arguments);
+    };
+
+    // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
+
+    var origLocalDescription = Object.getOwnPropertyDescriptor(
+        window.RTCPeerConnection.prototype, 'localDescription');
+    Object.defineProperty(window.RTCPeerConnection.prototype,
+        'localDescription', {
+          get: function() {
+            var pc = this;
+            var description = origLocalDescription.get.apply(this);
+            if (description.type === '') {
+              return description;
+            }
+            return replaceInternalStreamId(pc, description);
+          }
+        });
+
+    window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      // We can not yet check for sender instanceof RTCRtpSender
+      // since we shim RTPSender. So we check if sender._pc is set.
+      if (!sender._pc) {
+        throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
+            'does not implement interface RTCRtpSender.', 'TypeError');
+      }
+      var isLocal = sender._pc === pc;
+      if (!isLocal) {
+        throw new DOMException('Sender was not created by this connection.',
+            'InvalidAccessError');
+      }
+
+      // Search for the native stream the senders track belongs to.
+      pc._streams = pc._streams || {};
+      var stream;
+      Object.keys(pc._streams).forEach(function(streamid) {
+        var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
+          return sender.track === track;
+        });
+        if (hasTrack) {
+          stream = pc._streams[streamid];
+        }
+      });
+
+      if (stream) {
+        if (stream.getTracks().length === 1) {
+          // if this is the last track of the stream, remove the stream. This
+          // takes care of any shimmed _senders.
+          pc.removeStream(pc._reverseStreams[stream.id]);
+        } else {
+          // relying on the same odd chrome behaviour as above.
+          stream.removeTrack(sender.track);
+        }
+        pc.dispatchEvent(new Event('negotiationneeded'));
+      }
+    };
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        // Translate iceTransportPolicy to iceTransports,
+        // see https://code.google.com/p/webrtc/issues/detail?id=4869
+        // this was fixed in M56 along with unprefixing RTCPeerConnection.
+        logging('PeerConnection');
+        if (pcConfig && pcConfig.iceTransportPolicy) {
+          pcConfig.iceTransports = pcConfig.iceTransportPolicy;
+        }
+
+        return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.webkitRTCPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      if (window.webkitRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.webkitRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+    } else {
+      // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+      var OrigPeerConnection = window.RTCPeerConnection;
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (pcConfig && pcConfig.iceServers) {
+          var newIceServers = [];
+          for (var i = 0; i < pcConfig.iceServers.length; i++) {
+            var server = pcConfig.iceServers[i];
+            if (!server.hasOwnProperty('urls') &&
+                server.hasOwnProperty('url')) {
+              utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+              server = JSON.parse(JSON.stringify(server));
+              server.urls = server.url;
+              newIceServers.push(server);
+            } else {
+              newIceServers.push(pcConfig.iceServers[i]);
+            }
+          }
+          pcConfig.iceServers = newIceServers;
+        }
+        return new OrigPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+
+    var origGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(selector,
+        successCallback, errorCallback) {
+      var self = this;
+      var args = arguments;
+
+      // If selector is a function then we are in the old style stats so just
+      // pass back the original getStats format to avoid breaking old users.
+      if (arguments.length > 0 && typeof selector === 'function') {
+        return origGetStats.apply(this, arguments);
+      }
+
+      // When spec-style getStats is supported, return those when called with
+      // either no arguments or the selector argument is null.
+      if (origGetStats.length === 0 && (arguments.length === 0 ||
+          typeof arguments[0] !== 'function')) {
+        return origGetStats.apply(this, []);
+      }
+
+      var fixChromeStats_ = function(response) {
+        var standardReport = {};
+        var reports = response.result();
+        reports.forEach(function(report) {
+          var standardStats = {
+            id: report.id,
+            timestamp: report.timestamp,
+            type: {
+              localcandidate: 'local-candidate',
+              remotecandidate: 'remote-candidate'
+            }[report.type] || report.type
+          };
+          report.names().forEach(function(name) {
+            standardStats[name] = report.stat(name);
+          });
+          standardReport[standardStats.id] = standardStats;
+        });
+
+        return standardReport;
+      };
+
+      // shim getStats with maplike support
+      var makeMapStats = function(stats) {
+        return new Map(Object.keys(stats).map(function(key) {
+          return [key, stats[key]];
+        }));
+      };
+
+      if (arguments.length >= 2) {
+        var successCallbackWrapper_ = function(response) {
+          args[1](makeMapStats(fixChromeStats_(response)));
+        };
+
+        return origGetStats.apply(this, [successCallbackWrapper_,
+          arguments[0]]);
+      }
+
+      // promise-support
+      return new Promise(function(resolve, reject) {
+        origGetStats.apply(self, [
+          function(response) {
+            resolve(makeMapStats(fixChromeStats_(response)));
+          }, reject]);
+      }).then(successCallback, errorCallback);
+    };
+
+    // add promise support -- natively available in Chrome 51
+    if (browserDetails.version < 51) {
+      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+          .forEach(function(method) {
+            var nativeMethod = window.RTCPeerConnection.prototype[method];
+            window.RTCPeerConnection.prototype[method] = function() {
+              var args = arguments;
+              var self = this;
+              var promise = new Promise(function(resolve, reject) {
+                nativeMethod.apply(self, [args[0], resolve, reject]);
+              });
+              if (args.length < 2) {
+                return promise;
+              }
+              return promise.then(function() {
+                args[1].apply(null, []);
+              },
+              function(err) {
+                if (args.length >= 3) {
+                  args[2].apply(null, [err]);
+                }
+              });
+            };
+          });
+    }
+
+    // promise support for createOffer and createAnswer. Available (without
+    // bugs) since M52: crbug/619289
+    if (browserDetails.version < 52) {
+      ['createOffer', 'createAnswer'].forEach(function(method) {
+        var nativeMethod = window.RTCPeerConnection.prototype[method];
+        window.RTCPeerConnection.prototype[method] = function() {
+          var self = this;
+          if (arguments.length < 1 || (arguments.length === 1 &&
+              typeof arguments[0] === 'object')) {
+            var opts = arguments.length === 1 ? arguments[0] : undefined;
+            return new Promise(function(resolve, reject) {
+              nativeMethod.apply(self, [resolve, reject, opts]);
+            });
+          }
+          return nativeMethod.apply(this, arguments);
+        };
+      });
+    }
+
+    // shim implicit creation of RTCSessionDescription/RTCIceCandidate
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+  }
+};
+
+
+// Expose public methods.
+module.exports = {
+  shimMediaStream: chromeShim.shimMediaStream,
+  shimOnTrack: chromeShim.shimOnTrack,
+  shimAddTrackRemoveTrack: chromeShim.shimAddTrackRemoveTrack,
+  shimGetSendersWithDtmf: chromeShim.shimGetSendersWithDtmf,
+  shimSourceObject: chromeShim.shimSourceObject,
+  shimPeerConnection: chromeShim.shimPeerConnection,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils.js":11,"./getusermedia":6}],6:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+
+  var constraintsToChrome_ = function(c) {
+    if (typeof c !== 'object' || c.mandatory || c.optional) {
+      return c;
+    }
+    var cc = {};
+    Object.keys(c).forEach(function(key) {
+      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+        return;
+      }
+      var r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
+      if (r.exact !== undefined && typeof r.exact === 'number') {
+        r.min = r.max = r.exact;
+      }
+      var oldname_ = function(prefix, name) {
+        if (prefix) {
+          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+        }
+        return (name === 'deviceId') ? 'sourceId' : name;
+      };
+      if (r.ideal !== undefined) {
+        cc.optional = cc.optional || [];
+        var oc = {};
+        if (typeof r.ideal === 'number') {
+          oc[oldname_('min', key)] = r.ideal;
+          cc.optional.push(oc);
+          oc = {};
+          oc[oldname_('max', key)] = r.ideal;
+          cc.optional.push(oc);
+        } else {
+          oc[oldname_('', key)] = r.ideal;
+          cc.optional.push(oc);
+        }
+      }
+      if (r.exact !== undefined && typeof r.exact !== 'number') {
+        cc.mandatory = cc.mandatory || {};
+        cc.mandatory[oldname_('', key)] = r.exact;
+      } else {
+        ['min', 'max'].forEach(function(mix) {
+          if (r[mix] !== undefined) {
+            cc.mandatory = cc.mandatory || {};
+            cc.mandatory[oldname_(mix, key)] = r[mix];
+          }
+        });
+      }
+    });
+    if (c.advanced) {
+      cc.optional = (cc.optional || []).concat(c.advanced);
+    }
+    return cc;
+  };
+
+  var shimConstraints_ = function(constraints, func) {
+    if (browserDetails.version >= 61) {
+      return func(constraints);
+    }
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (constraints && typeof constraints.audio === 'object') {
+      var remap = function(obj, a, b) {
+        if (a in obj && !(b in obj)) {
+          obj[b] = obj[a];
+          delete obj[a];
+        }
+      };
+      constraints = JSON.parse(JSON.stringify(constraints));
+      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
+      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
+      constraints.audio = constraintsToChrome_(constraints.audio);
+    }
+    if (constraints && typeof constraints.video === 'object') {
+      // Shim facingMode for mobile & surface pro.
+      var face = constraints.video.facingMode;
+      face = face && ((typeof face === 'object') ? face : {ideal: face});
+      var getSupportedFacingModeLies = browserDetails.version < 66;
+
+      if ((face && (face.exact === 'user' || face.exact === 'environment' ||
+                    face.ideal === 'user' || face.ideal === 'environment')) &&
+          !(navigator.mediaDevices.getSupportedConstraints &&
+            navigator.mediaDevices.getSupportedConstraints().facingMode &&
+            !getSupportedFacingModeLies)) {
+        delete constraints.video.facingMode;
+        var matches;
+        if (face.exact === 'environment' || face.ideal === 'environment') {
+          matches = ['back', 'rear'];
+        } else if (face.exact === 'user' || face.ideal === 'user') {
+          matches = ['front'];
+        }
+        if (matches) {
+          // Look for matches in label, or use last cam for back (typical).
+          return navigator.mediaDevices.enumerateDevices()
+          .then(function(devices) {
+            devices = devices.filter(function(d) {
+              return d.kind === 'videoinput';
+            });
+            var dev = devices.find(function(d) {
+              return matches.some(function(match) {
+                return d.label.toLowerCase().indexOf(match) !== -1;
+              });
+            });
+            if (!dev && devices.length && matches.indexOf('back') !== -1) {
+              dev = devices[devices.length - 1]; // more likely the back cam
+            }
+            if (dev) {
+              constraints.video.deviceId = face.exact ? {exact: dev.deviceId} :
+                                                        {ideal: dev.deviceId};
+            }
+            constraints.video = constraintsToChrome_(constraints.video);
+            logging('chrome: ' + JSON.stringify(constraints));
+            return func(constraints);
+          });
+        }
+      }
+      constraints.video = constraintsToChrome_(constraints.video);
+    }
+    logging('chrome: ' + JSON.stringify(constraints));
+    return func(constraints);
+  };
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        PermissionDeniedError: 'NotAllowedError',
+        InvalidStateError: 'NotReadableError',
+        DevicesNotFoundError: 'NotFoundError',
+        ConstraintNotSatisfiedError: 'OverconstrainedError',
+        TrackStartError: 'NotReadableError',
+        MediaDeviceFailedDueToShutdown: 'NotReadableError',
+        MediaDeviceKillSwitchOn: 'NotReadableError'
+      }[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraintName,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    shimConstraints_(constraints, function(c) {
+      navigator.webkitGetUserMedia(c, onSuccess, function(e) {
+        if (onError) {
+          onError(shimError_(e));
+        }
+      });
+    });
+  };
+
+  navigator.getUserMedia = getUserMedia_;
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      navigator.getUserMedia(constraints, resolve, reject);
+    });
+  };
+
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {
+      getUserMedia: getUserMediaPromise_,
+      enumerateDevices: function() {
+        return new Promise(function(resolve) {
+          var kinds = {audio: 'audioinput', video: 'videoinput'};
+          return window.MediaStreamTrack.getSources(function(devices) {
+            resolve(devices.map(function(device) {
+              return {label: device.label,
+                kind: kinds[device.kind],
+                deviceId: device.id,
+                groupId: ''};
+            }));
+          });
+        });
+      },
+      getSupportedConstraints: function() {
+        return {
+          deviceId: true, echoCancellation: true, facingMode: true,
+          frameRate: true, height: true, width: true
+        };
+      }
+    };
+  }
+
+  // A shim for getUserMedia method on the mediaDevices object.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (!navigator.mediaDevices.getUserMedia) {
+    navigator.mediaDevices.getUserMedia = function(constraints) {
+      return getUserMediaPromise_(constraints);
+    };
+  } else {
+    // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
+    // function which returns a Promise, it does not accept spec-style
+    // constraints.
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(cs) {
+      return shimConstraints_(cs, function(c) {
+        return origGetUserMedia(c).then(function(stream) {
+          if (c.audio && !stream.getAudioTracks().length ||
+              c.video && !stream.getVideoTracks().length) {
+            stream.getTracks().forEach(function(track) {
+              track.stop();
+            });
+            throw new DOMException('', 'NotFoundError');
+          }
+          return stream;
+        }, function(e) {
+          return Promise.reject(shimError_(e));
+        });
+      });
+    };
+  }
+
+  // Dummy devicechange event methods.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
+    navigator.mediaDevices.addEventListener = function() {
+      logging('Dummy mediaDevices.addEventListener called.');
+    };
+  }
+  if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
+    navigator.mediaDevices.removeEventListener = function() {
+      logging('Dummy mediaDevices.removeEventListener called.');
+    };
+  }
+};
+
+},{"../utils.js":11}],7:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+var utils = require('./utils');
+
+// Wraps the peerconnection event eventNameToWrap in a function
+// which returns the modified event object.
+function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  var proto = window.RTCPeerConnection.prototype;
+  var nativeAddEventListener = proto.addEventListener;
+  proto.addEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap) {
+      return nativeAddEventListener.apply(this, arguments);
+    }
+    var wrappedCallback = function(e) {
+      cb(wrapper(e));
+    };
+    this._eventMap = this._eventMap || {};
+    this._eventMap[cb] = wrappedCallback;
+    return nativeAddEventListener.apply(this, [nativeEventName,
+      wrappedCallback]);
+  };
+
+  var nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap
+        || !this._eventMap[cb]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    var unwrappedCb = this._eventMap[cb];
+    delete this._eventMap[cb];
+    return nativeRemoveEventListener.apply(this, [nativeEventName,
+      unwrappedCb]);
+  };
+
+  Object.defineProperty(proto, 'on' + eventNameToWrap, {
+    get: function() {
+      return this['_on' + eventNameToWrap];
+    },
+    set: function(cb) {
+      if (this['_on' + eventNameToWrap]) {
+        this.removeEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap]);
+        delete this['_on' + eventNameToWrap];
+      }
+      if (cb) {
+        this.addEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap] = cb);
+      }
+    }
+  });
+}
+
+module.exports = {
+  shimRTCIceCandidate: function(window) {
+    // foundation is arbitrarily chosen as an indicator for full support for
+    // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
+    if (window.RTCIceCandidate && 'foundation' in
+        window.RTCIceCandidate.prototype) {
+      return;
+    }
+
+    var NativeRTCIceCandidate = window.RTCIceCandidate;
+    window.RTCIceCandidate = function(args) {
+      // Remove the a= which shouldn't be part of the candidate string.
+      if (typeof args === 'object' && args.candidate &&
+          args.candidate.indexOf('a=') === 0) {
+        args = JSON.parse(JSON.stringify(args));
+        args.candidate = args.candidate.substr(2);
+      }
+
+      // Augment the native candidate with the parsed fields.
+      var nativeCandidate = new NativeRTCIceCandidate(args);
+      var parsedCandidate = SDPUtils.parseCandidate(args.candidate);
+      var augmentedCandidate = Object.assign(nativeCandidate,
+          parsedCandidate);
+
+      // Add a serializer that does not serialize the extra attributes.
+      augmentedCandidate.toJSON = function() {
+        return {
+          candidate: augmentedCandidate.candidate,
+          sdpMid: augmentedCandidate.sdpMid,
+          sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
+          usernameFragment: augmentedCandidate.usernameFragment,
+        };
+      };
+      return augmentedCandidate;
+    };
+
+    // Hook up the augmented candidate in onicecandidate and
+    // addEventListener('icecandidate', ...)
+    wrapPeerConnectionEvent(window, 'icecandidate', function(e) {
+      if (e.candidate) {
+        Object.defineProperty(e, 'candidate', {
+          value: new window.RTCIceCandidate(e.candidate),
+          writable: 'false'
+        });
+      }
+      return e;
+    });
+  },
+
+  // shimCreateObjectURL must be called before shimSourceObject to avoid loop.
+
+  shimCreateObjectURL: function(window) {
+    var URL = window && window.URL;
+
+    if (!(typeof window === 'object' && window.HTMLMediaElement &&
+          'srcObject' in window.HTMLMediaElement.prototype &&
+        URL.createObjectURL && URL.revokeObjectURL)) {
+      // Only shim CreateObjectURL using srcObject if srcObject exists.
+      return undefined;
+    }
+
+    var nativeCreateObjectURL = URL.createObjectURL.bind(URL);
+    var nativeRevokeObjectURL = URL.revokeObjectURL.bind(URL);
+    var streams = new Map(), newId = 0;
+
+    URL.createObjectURL = function(stream) {
+      if ('getTracks' in stream) {
+        var url = 'polyblob:' + (++newId);
+        streams.set(url, stream);
+        utils.deprecated('URL.createObjectURL(stream)',
+            'elem.srcObject = stream');
+        return url;
+      }
+      return nativeCreateObjectURL(stream);
+    };
+    URL.revokeObjectURL = function(url) {
+      nativeRevokeObjectURL(url);
+      streams.delete(url);
+    };
+
+    var dsc = Object.getOwnPropertyDescriptor(window.HTMLMediaElement.prototype,
+                                              'src');
+    Object.defineProperty(window.HTMLMediaElement.prototype, 'src', {
+      get: function() {
+        return dsc.get.apply(this);
+      },
+      set: function(url) {
+        this.srcObject = streams.get(url) || null;
+        return dsc.set.apply(this, [url]);
+      }
+    });
+
+    var nativeSetAttribute = window.HTMLMediaElement.prototype.setAttribute;
+    window.HTMLMediaElement.prototype.setAttribute = function() {
+      if (arguments.length === 2 &&
+          ('' + arguments[0]).toLowerCase() === 'src') {
+        this.srcObject = streams.get(arguments[1]) || null;
+      }
+      return nativeSetAttribute.apply(this, arguments);
+    };
+  }
+};
+
+},{"./utils":11,"sdp":2}],8:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+
+var firefoxShim = {
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+            this.removeEventListener('addstream', this._ontrackpoly);
+          }
+          this.addEventListener('track', this._ontrack = f);
+          this.addEventListener('addstream', this._ontrackpoly = function(e) {
+            e.stream.getTracks().forEach(function(track) {
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = {track: track};
+              event.transceiver = {receiver: event.receiver};
+              event.streams = [e.stream];
+              this.dispatchEvent(event);
+            }.bind(this));
+          }.bind(this));
+        }
+      });
+    }
+    if (typeof window === 'object' && window.RTCTrackEvent &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        !('transceiver' in window.RTCTrackEvent.prototype)) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this.mozSrcObject;
+          },
+          set: function(stream) {
+            this.mozSrcObject = stream;
+          }
+        });
+      }
+    }
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (typeof window !== 'object' || !(window.RTCPeerConnection ||
+        window.mozRTCPeerConnection)) {
+      return; // probably media.peerconnection.enabled=false in about:config
+    }
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (browserDetails.version < 38) {
+          // .urls is not supported in FF < 38.
+          // create RTCIceServers with a single url.
+          if (pcConfig && pcConfig.iceServers) {
+            var newIceServers = [];
+            for (var i = 0; i < pcConfig.iceServers.length; i++) {
+              var server = pcConfig.iceServers[i];
+              if (server.hasOwnProperty('urls')) {
+                for (var j = 0; j < server.urls.length; j++) {
+                  var newServer = {
+                    url: server.urls[j]
+                  };
+                  if (server.urls[j].indexOf('turn') === 0) {
+                    newServer.username = server.username;
+                    newServer.credential = server.credential;
+                  }
+                  newIceServers.push(newServer);
+                }
+              } else {
+                newIceServers.push(pcConfig.iceServers[i]);
+              }
+            }
+            pcConfig.iceServers = newIceServers;
+          }
+        }
+        return new window.mozRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.mozRTCPeerConnection.prototype;
+
+      // wrap static methods. Currently just generateCertificate.
+      if (window.mozRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.mozRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+
+      window.RTCSessionDescription = window.mozRTCSessionDescription;
+      window.RTCIceCandidate = window.mozRTCIceCandidate;
+    }
+
+    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+
+    // shim getStats with maplike support
+    var makeMapStats = function(stats) {
+      var map = new Map();
+      Object.keys(stats).forEach(function(key) {
+        map.set(key, stats[key]);
+        map[key] = stats[key];
+      });
+      return map;
+    };
+
+    var modernStatsTypes = {
+      inboundrtp: 'inbound-rtp',
+      outboundrtp: 'outbound-rtp',
+      candidatepair: 'candidate-pair',
+      localcandidate: 'local-candidate',
+      remotecandidate: 'remote-candidate'
+    };
+
+    var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(
+      selector,
+      onSucc,
+      onErr
+    ) {
+      return nativeGetStats.apply(this, [selector || null])
+        .then(function(stats) {
+          if (browserDetails.version < 48) {
+            stats = makeMapStats(stats);
+          }
+          if (browserDetails.version < 53 && !onSucc) {
+            // Shim only promise getStats with spec-hyphens in type names
+            // Leave callback version alone; misc old uses of forEach before Map
+            try {
+              stats.forEach(function(stat) {
+                stat.type = modernStatsTypes[stat.type] || stat.type;
+              });
+            } catch (e) {
+              if (e.name !== 'TypeError') {
+                throw e;
+              }
+              // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
+              stats.forEach(function(stat, i) {
+                stats.set(i, Object.assign({}, stat, {
+                  type: modernStatsTypes[stat.type] || stat.type
+                }));
+              });
+            }
+          }
+          return stats;
+        })
+        .then(onSucc, onErr);
+    };
+  },
+
+  shimRemoveStream: function(window) {
+    if (!window.RTCPeerConnection ||
+        'removeStream' in window.RTCPeerConnection.prototype) {
+      return;
+    }
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      utils.deprecated('removeStream', 'removeTrack');
+      this.getSenders().forEach(function(sender) {
+        if (sender.track && stream.getTracks().indexOf(sender.track) !== -1) {
+          pc.removeTrack(sender);
+        }
+      });
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimOnTrack: firefoxShim.shimOnTrack,
+  shimSourceObject: firefoxShim.shimSourceObject,
+  shimPeerConnection: firefoxShim.shimPeerConnection,
+  shimRemoveStream: firefoxShim.shimRemoveStream,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils":11,"./getusermedia":9}],9:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+  var MediaStreamTrack = window && window.MediaStreamTrack;
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        InternalError: 'NotReadableError',
+        NotSupportedError: 'TypeError',
+        PermissionDeniedError: 'NotAllowedError',
+        SecurityError: 'NotAllowedError'
+      }[e.name] || e.name,
+      message: {
+        'The operation is insecure.': 'The request is not allowed by the ' +
+        'user agent or the platform in the current context.'
+      }[e.message] || e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  // getUserMedia constraints shim.
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    var constraintsToFF37_ = function(c) {
+      if (typeof c !== 'object' || c.require) {
+        return c;
+      }
+      var require = [];
+      Object.keys(c).forEach(function(key) {
+        if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+          return;
+        }
+        var r = c[key] = (typeof c[key] === 'object') ?
+            c[key] : {ideal: c[key]};
+        if (r.min !== undefined ||
+            r.max !== undefined || r.exact !== undefined) {
+          require.push(key);
+        }
+        if (r.exact !== undefined) {
+          if (typeof r.exact === 'number') {
+            r. min = r.max = r.exact;
+          } else {
+            c[key] = r.exact;
+          }
+          delete r.exact;
+        }
+        if (r.ideal !== undefined) {
+          c.advanced = c.advanced || [];
+          var oc = {};
+          if (typeof r.ideal === 'number') {
+            oc[key] = {min: r.ideal, max: r.ideal};
+          } else {
+            oc[key] = r.ideal;
+          }
+          c.advanced.push(oc);
+          delete r.ideal;
+          if (!Object.keys(r).length) {
+            delete c[key];
+          }
+        }
+      });
+      if (require.length) {
+        c.require = require;
+      }
+      return c;
+    };
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (browserDetails.version < 38) {
+      logging('spec: ' + JSON.stringify(constraints));
+      if (constraints.audio) {
+        constraints.audio = constraintsToFF37_(constraints.audio);
+      }
+      if (constraints.video) {
+        constraints.video = constraintsToFF37_(constraints.video);
+      }
+      logging('ff37: ' + JSON.stringify(constraints));
+    }
+    return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
+      onError(shimError_(e));
+    });
+  };
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      getUserMedia_(constraints, resolve, reject);
+    });
+  };
+
+  // Shim for mediaDevices on older versions.
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
+      addEventListener: function() { },
+      removeEventListener: function() { }
+    };
+  }
+  navigator.mediaDevices.enumerateDevices =
+      navigator.mediaDevices.enumerateDevices || function() {
+        return new Promise(function(resolve) {
+          var infos = [
+            {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
+            {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
+          ];
+          resolve(infos);
+        });
+      };
+
+  if (browserDetails.version < 41) {
+    // Work around http://bugzil.la/1169665
+    var orgEnumerateDevices =
+        navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
+    navigator.mediaDevices.enumerateDevices = function() {
+      return orgEnumerateDevices().then(undefined, function(e) {
+        if (e.name === 'NotFoundError') {
+          return [];
+        }
+        throw e;
+      });
+    };
+  }
+  if (browserDetails.version < 49) {
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      return origGetUserMedia(c).then(function(stream) {
+        // Work around https://bugzil.la/802326
+        if (c.audio && !stream.getAudioTracks().length ||
+            c.video && !stream.getVideoTracks().length) {
+          stream.getTracks().forEach(function(track) {
+            track.stop();
+          });
+          throw new DOMException('The object can not be found here.',
+                                 'NotFoundError');
+        }
+        return stream;
+      }, function(e) {
+        return Promise.reject(shimError_(e));
+      });
+    };
+  }
+  if (!(browserDetails.version > 55 &&
+      'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
+    var remap = function(obj, a, b) {
+      if (a in obj && !(b in obj)) {
+        obj[b] = obj[a];
+        delete obj[a];
+      }
+    };
+
+    var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      if (typeof c === 'object' && typeof c.audio === 'object') {
+        c = JSON.parse(JSON.stringify(c));
+        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
+        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
+      }
+      return nativeGetUserMedia(c);
+    };
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
+      var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
+      MediaStreamTrack.prototype.getSettings = function() {
+        var obj = nativeGetSettings.apply(this, arguments);
+        remap(obj, 'mozAutoGainControl', 'autoGainControl');
+        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
+        return obj;
+      };
+    }
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
+      var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
+      MediaStreamTrack.prototype.applyConstraints = function(c) {
+        if (this.kind === 'audio' && typeof c === 'object') {
+          c = JSON.parse(JSON.stringify(c));
+          remap(c, 'autoGainControl', 'mozAutoGainControl');
+          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
+        }
+        return nativeApplyConstraints.apply(this, [c]);
+      };
+    }
+  }
+  navigator.getUserMedia = function(constraints, onSuccess, onError) {
+    if (browserDetails.version < 44) {
+      return getUserMedia_(constraints, onSuccess, onError);
+    }
+    // Replace Firefox 44+'s deprecation warning with unprefixed version.
+    utils.deprecated('navigator.getUserMedia',
+        'navigator.mediaDevices.getUserMedia');
+    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
+  };
+};
+
+},{"../utils":11}],10:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+'use strict';
+var utils = require('../utils');
+
+var safariShim = {
+  // TODO: DrAlex, should be here, double check against LayoutTests
+
+  // TODO: once the back-end for the mac port is done, add.
+  // TODO: check for webkitGTK+
+  // shimPeerConnection: function() { },
+
+  shimLocalStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getLocalStreams = function() {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        return this._localStreams;
+      };
+    }
+    if (!('getStreamById' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getStreamById = function(id) {
+        var result = null;
+        if (this._localStreams) {
+          this._localStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        if (this._remoteStreams) {
+          this._remoteStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        return result;
+      };
+    }
+    if (!('addStream' in window.RTCPeerConnection.prototype)) {
+      var _addTrack = window.RTCPeerConnection.prototype.addTrack;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        if (this._localStreams.indexOf(stream) === -1) {
+          this._localStreams.push(stream);
+        }
+        var self = this;
+        stream.getTracks().forEach(function(track) {
+          _addTrack.call(self, track, stream);
+        });
+      };
+
+      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+        if (stream) {
+          if (!this._localStreams) {
+            this._localStreams = [stream];
+          } else if (this._localStreams.indexOf(stream) === -1) {
+            this._localStreams.push(stream);
+          }
+        }
+        return _addTrack.call(this, track, stream);
+      };
+    }
+    if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        var index = this._localStreams.indexOf(stream);
+        if (index === -1) {
+          return;
+        }
+        this._localStreams.splice(index, 1);
+        var self = this;
+        var tracks = stream.getTracks();
+        this.getSenders().forEach(function(sender) {
+          if (tracks.indexOf(sender.track) !== -1) {
+            self.removeTrack(sender);
+          }
+        });
+      };
+    }
+  },
+  shimRemoteStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getRemoteStreams = function() {
+        return this._remoteStreams ? this._remoteStreams : [];
+      };
+    }
+    if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
+        get: function() {
+          return this._onaddstream;
+        },
+        set: function(f) {
+          if (this._onaddstream) {
+            this.removeEventListener('addstream', this._onaddstream);
+            this.removeEventListener('track', this._onaddstreampoly);
+          }
+          this.addEventListener('addstream', this._onaddstream = f);
+          this.addEventListener('track', this._onaddstreampoly = function(e) {
+            var stream = e.streams[0];
+            if (!this._remoteStreams) {
+              this._remoteStreams = [];
+            }
+            if (this._remoteStreams.indexOf(stream) >= 0) {
+              return;
+            }
+            this._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = e.streams[0];
+            this.dispatchEvent(event);
+          }.bind(this));
+        }
+      });
+    }
+  },
+  shimCallbacksAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    var prototype = window.RTCPeerConnection.prototype;
+    var createOffer = prototype.createOffer;
+    var createAnswer = prototype.createAnswer;
+    var setLocalDescription = prototype.setLocalDescription;
+    var setRemoteDescription = prototype.setRemoteDescription;
+    var addIceCandidate = prototype.addIceCandidate;
+
+    prototype.createOffer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createOffer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    prototype.createAnswer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createAnswer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    var withCallback = function(description, successCallback, failureCallback) {
+      var promise = setLocalDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setLocalDescription = withCallback;
+
+    withCallback = function(description, successCallback, failureCallback) {
+      var promise = setRemoteDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setRemoteDescription = withCallback;
+
+    withCallback = function(candidate, successCallback, failureCallback) {
+      var promise = addIceCandidate.apply(this, [candidate]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.addIceCandidate = withCallback;
+  },
+  shimGetUserMedia: function(window) {
+    var navigator = window && window.navigator;
+
+    if (!navigator.getUserMedia) {
+      if (navigator.webkitGetUserMedia) {
+        navigator.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
+      } else if (navigator.mediaDevices &&
+          navigator.mediaDevices.getUserMedia) {
+        navigator.getUserMedia = function(constraints, cb, errcb) {
+          navigator.mediaDevices.getUserMedia(constraints)
+          .then(cb, errcb);
+        }.bind(navigator);
+      }
+    }
+  },
+  shimRTCIceServerUrls: function(window) {
+    // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+    var OrigPeerConnection = window.RTCPeerConnection;
+    window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+      if (pcConfig && pcConfig.iceServers) {
+        var newIceServers = [];
+        for (var i = 0; i < pcConfig.iceServers.length; i++) {
+          var server = pcConfig.iceServers[i];
+          if (!server.hasOwnProperty('urls') &&
+              server.hasOwnProperty('url')) {
+            utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+            server = JSON.parse(JSON.stringify(server));
+            server.urls = server.url;
+            delete server.url;
+            newIceServers.push(server);
+          } else {
+            newIceServers.push(pcConfig.iceServers[i]);
+          }
+        }
+        pcConfig.iceServers = newIceServers;
+      }
+      return new OrigPeerConnection(pcConfig, pcConstraints);
+    };
+    window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+    // wrap static methods. Currently just generateCertificate.
+    if ('generateCertificate' in window.RTCPeerConnection) {
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+  },
+  shimTrackEventTransceiver: function(window) {
+    // Add event.transceiver member over deprecated event.receiver
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        // can't check 'transceiver' in window.RTCTrackEvent.prototype, as it is
+        // defined for some reason even when window.RTCTransceiver is not.
+        !window.RTCTransceiver) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimCreateOfferLegacy: function(window) {
+    var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+    window.RTCPeerConnection.prototype.createOffer = function(offerOptions) {
+      var pc = this;
+      if (offerOptions) {
+        var audioTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'audio';
+        });
+        if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
+          if (audioTransceiver.direction === 'sendrecv') {
+            audioTransceiver.setDirection('sendonly');
+          } else if (audioTransceiver.direction === 'recvonly') {
+            audioTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveAudio === true &&
+            !audioTransceiver) {
+          pc.addTransceiver('audio');
+        }
+
+        var videoTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'video';
+        });
+        if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
+          if (videoTransceiver.direction === 'sendrecv') {
+            videoTransceiver.setDirection('sendonly');
+          } else if (videoTransceiver.direction === 'recvonly') {
+            videoTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveVideo === true &&
+            !videoTransceiver) {
+          pc.addTransceiver('video');
+        }
+      }
+      return origCreateOffer.apply(pc, arguments);
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimCallbacksAPI: safariShim.shimCallbacksAPI,
+  shimLocalStreamsAPI: safariShim.shimLocalStreamsAPI,
+  shimRemoteStreamsAPI: safariShim.shimRemoteStreamsAPI,
+  shimGetUserMedia: safariShim.shimGetUserMedia,
+  shimRTCIceServerUrls: safariShim.shimRTCIceServerUrls,
+  shimTrackEventTransceiver: safariShim.shimTrackEventTransceiver,
+  shimCreateOfferLegacy: safariShim.shimCreateOfferLegacy
+  // TODO
+  // shimPeerConnection: safariShim.shimPeerConnection
+};
+
+},{"../utils":11}],11:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var logDisabled_ = true;
+var deprecationWarnings_ = true;
+
+// Utility methods.
+var utils = {
+  disableLog: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    logDisabled_ = bool;
+    return (bool) ? 'adapter.js logging disabled' :
+        'adapter.js logging enabled';
+  },
+
+  /**
+   * Disable or enable deprecation warnings
+   * @param {!boolean} bool set to true to disable warnings.
+   */
+  disableWarnings: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    deprecationWarnings_ = !bool;
+    return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
+  },
+
+  log: function() {
+    if (typeof window === 'object') {
+      if (logDisabled_) {
+        return;
+      }
+      if (typeof console !== 'undefined' && typeof console.log === 'function') {
+        console.log.apply(console, arguments);
+      }
+    }
+  },
+
+  /**
+   * Shows a deprecation warning suggesting the modern and spec-compatible API.
+   */
+  deprecated: function(oldMethod, newMethod) {
+    if (!deprecationWarnings_) {
+      return;
+    }
+    console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
+        ' instead.');
+  },
+
+  /**
+   * Extract browser version out of the provided user agent string.
+   *
+   * @param {!string} uastring userAgent string.
+   * @param {!string} expr Regular expression used as match criteria.
+   * @param {!number} pos position in the version string to be returned.
+   * @return {!number} browser version.
+   */
+  extractVersion: function(uastring, expr, pos) {
+    var match = uastring.match(expr);
+    return match && match.length >= pos && parseInt(match[pos], 10);
+  },
+
+  /**
+   * Browser detector.
+   *
+   * @return {object} result containing browser and version
+   *     properties.
+   */
+  detectBrowser: function(window) {
+    var navigator = window && window.navigator;
+
+    // Returned result object.
+    var result = {};
+    result.browser = null;
+    result.version = null;
+
+    // Fail early if it's not a browser
+    if (typeof window === 'undefined' || !window.navigator) {
+      result.browser = 'Not a browser.';
+      return result;
+    }
+
+    // Firefox.
+    if (navigator.mozGetUserMedia) {
+      result.browser = 'firefox';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Firefox\/(\d+)\./, 1);
+    } else if (navigator.webkitGetUserMedia) {
+      // Chrome, Chromium, Webview, Opera, all use the chrome shim for now
+      if (window.webkitRTCPeerConnection) {
+        result.browser = 'chrome';
+        result.version = this.extractVersion(navigator.userAgent,
+          /Chrom(e|ium)\/(\d+)\./, 2);
+      } else { // Safari (in an unpublished version) or unknown webkit-based.
+        if (navigator.userAgent.match(/Version\/(\d+).(\d+)/)) {
+          result.browser = 'safari';
+          result.version = this.extractVersion(navigator.userAgent,
+            /AppleWebKit\/(\d+)\./, 1);
+        } else { // unknown webkit-based browser.
+          result.browser = 'Unsupported webkit-based browser ' +
+              'with GUM support but no WebRTC support.';
+          return result;
+        }
+      }
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) { // Edge.
+      result.browser = 'edge';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Edge\/(\d+).(\d+)$/, 2);
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) {
+        // Safari, with webkitGetUserMedia removed.
+      result.browser = 'safari';
+      result.version = this.extractVersion(navigator.userAgent,
+          /AppleWebKit\/(\d+)\./, 1);
+    } else { // Default fallthrough: not supported.
+      result.browser = 'Not a supported browser.';
+      return result;
+    }
+
+    return result;
+  },
+
+};
+
+// Export.
+module.exports = {
+  log: utils.log,
+  deprecated: utils.deprecated,
+  disableLog: utils.disableLog,
+  disableWarnings: utils.disableWarnings,
+  extractVersion: utils.extractVersion,
+  shimCreateObjectURL: utils.shimCreateObjectURL,
+  detectBrowser: utils.detectBrowser.bind(utils)
+};
+
+},{}]},{},[3]);

+ 4470 - 0
support/client/lib/vwf/view/webrtc/dist/adapter_no_global.js

@@ -0,0 +1,4470 @@
+(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+
+function writeMediaSection(transceiver, caps, type, stream, dtlsRole) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : dtlsRole || 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+}
+
+// Edge does not like
+// 1) stun: filtered after 14393 unless ?transport=udp is present
+// 2) turn: that does not have all of turn:host:port?transport=udp
+// 3) turn: with ipv6 addresses
+// 4) turn: occurring muliple times
+function filterIceServers(iceServers, edgeVersion) {
+  var hasTurn = false;
+  iceServers = JSON.parse(JSON.stringify(iceServers));
+  return iceServers.filter(function(server) {
+    if (server && (server.urls || server.url)) {
+      var urls = server.urls || server.url;
+      if (server.url && !server.urls) {
+        console.warn('RTCIceServer.url is deprecated! Use urls instead.');
+      }
+      var isString = typeof urls === 'string';
+      if (isString) {
+        urls = [urls];
+      }
+      urls = urls.filter(function(url) {
+        var validTurn = url.indexOf('turn:') === 0 &&
+            url.indexOf('transport=udp') !== -1 &&
+            url.indexOf('turn:[') === -1 &&
+            !hasTurn;
+
+        if (validTurn) {
+          hasTurn = true;
+          return true;
+        }
+        return url.indexOf('stun:') === 0 && edgeVersion >= 14393 &&
+            url.indexOf('?transport=udp') === -1;
+      });
+
+      delete server.url;
+      server.urls = isString ? urls[0] : urls;
+      return !!urls.length;
+    }
+    return false;
+  });
+}
+
+// Determines the intersection of local and remote capabilities.
+function getCommonCapabilities(localCapabilities, remoteCapabilities) {
+  var commonCapabilities = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: []
+  };
+
+  var findCodecByPayloadType = function(pt, codecs) {
+    pt = parseInt(pt, 10);
+    for (var i = 0; i < codecs.length; i++) {
+      if (codecs[i].payloadType === pt ||
+          codecs[i].preferredPayloadType === pt) {
+        return codecs[i];
+      }
+    }
+  };
+
+  var rtxCapabilityMatches = function(lRtx, rRtx, lCodecs, rCodecs) {
+    var lCodec = findCodecByPayloadType(lRtx.parameters.apt, lCodecs);
+    var rCodec = findCodecByPayloadType(rRtx.parameters.apt, rCodecs);
+    return lCodec && rCodec &&
+        lCodec.name.toLowerCase() === rCodec.name.toLowerCase();
+  };
+
+  localCapabilities.codecs.forEach(function(lCodec) {
+    for (var i = 0; i < remoteCapabilities.codecs.length; i++) {
+      var rCodec = remoteCapabilities.codecs[i];
+      if (lCodec.name.toLowerCase() === rCodec.name.toLowerCase() &&
+          lCodec.clockRate === rCodec.clockRate) {
+        if (lCodec.name.toLowerCase() === 'rtx' &&
+            lCodec.parameters && rCodec.parameters.apt) {
+          // for RTX we need to find the local rtx that has a apt
+          // which points to the same local codec as the remote one.
+          if (!rtxCapabilityMatches(lCodec, rCodec,
+              localCapabilities.codecs, remoteCapabilities.codecs)) {
+            continue;
+          }
+        }
+        rCodec = JSON.parse(JSON.stringify(rCodec)); // deepcopy
+        // number of channels is the highest common number of channels
+        rCodec.numChannels = Math.min(lCodec.numChannels,
+            rCodec.numChannels);
+        // push rCodec so we reply with offerer payload type
+        commonCapabilities.codecs.push(rCodec);
+
+        // determine common feedback mechanisms
+        rCodec.rtcpFeedback = rCodec.rtcpFeedback.filter(function(fb) {
+          for (var j = 0; j < lCodec.rtcpFeedback.length; j++) {
+            if (lCodec.rtcpFeedback[j].type === fb.type &&
+                lCodec.rtcpFeedback[j].parameter === fb.parameter) {
+              return true;
+            }
+          }
+          return false;
+        });
+        // FIXME: also need to determine .parameters
+        //  see https://github.com/openpeer/ortc/issues/569
+        break;
+      }
+    }
+  });
+
+  localCapabilities.headerExtensions.forEach(function(lHeaderExtension) {
+    for (var i = 0; i < remoteCapabilities.headerExtensions.length;
+         i++) {
+      var rHeaderExtension = remoteCapabilities.headerExtensions[i];
+      if (lHeaderExtension.uri === rHeaderExtension.uri) {
+        commonCapabilities.headerExtensions.push(rHeaderExtension);
+        break;
+      }
+    }
+  });
+
+  // FIXME: fecMechanisms
+  return commonCapabilities;
+}
+
+// is action=setLocalDescription with type allowed in signalingState
+function isActionAllowedInSignalingState(action, type, signalingState) {
+  return {
+    offer: {
+      setLocalDescription: ['stable', 'have-local-offer'],
+      setRemoteDescription: ['stable', 'have-remote-offer']
+    },
+    answer: {
+      setLocalDescription: ['have-remote-offer', 'have-local-pranswer'],
+      setRemoteDescription: ['have-local-offer', 'have-remote-pranswer']
+    }
+  }[type][action].indexOf(signalingState) !== -1;
+}
+
+function maybeAddCandidate(iceTransport, candidate) {
+  // Edge's internal representation adds some fields therefore
+  // not all fieldѕ are taken into account.
+  var alreadyAdded = iceTransport.getRemoteCandidates()
+      .find(function(remoteCandidate) {
+        return candidate.foundation === remoteCandidate.foundation &&
+            candidate.ip === remoteCandidate.ip &&
+            candidate.port === remoteCandidate.port &&
+            candidate.priority === remoteCandidate.priority &&
+            candidate.protocol === remoteCandidate.protocol &&
+            candidate.type === remoteCandidate.type;
+      });
+  if (!alreadyAdded) {
+    iceTransport.addRemoteCandidate(candidate);
+  }
+  return !alreadyAdded;
+}
+
+module.exports = function(window, edgeVersion) {
+  var RTCPeerConnection = function(config) {
+    var self = this;
+
+    var _eventTarget = document.createDocumentFragment();
+    ['addEventListener', 'removeEventListener', 'dispatchEvent']
+        .forEach(function(method) {
+          self[method] = _eventTarget[method].bind(_eventTarget);
+        });
+
+    this.onicecandidate = null;
+    this.onaddstream = null;
+    this.ontrack = null;
+    this.onremovestream = null;
+    this.onsignalingstatechange = null;
+    this.oniceconnectionstatechange = null;
+    this.onicegatheringstatechange = null;
+    this.onnegotiationneeded = null;
+    this.ondatachannel = null;
+    this.canTrickleIceCandidates = null;
+
+    this.needNegotiation = false;
+
+    this.localStreams = [];
+    this.remoteStreams = [];
+
+    this.localDescription = null;
+    this.remoteDescription = null;
+
+    this.signalingState = 'stable';
+    this.iceConnectionState = 'new';
+    this.iceGatheringState = 'new';
+
+    config = JSON.parse(JSON.stringify(config || {}));
+
+    this.usingBundle = config.bundlePolicy === 'max-bundle';
+    if (config.rtcpMuxPolicy === 'negotiate') {
+      var e = new Error('rtcpMuxPolicy \'negotiate\' is not supported');
+      e.name = 'NotSupportedError';
+      throw(e);
+    } else if (!config.rtcpMuxPolicy) {
+      config.rtcpMuxPolicy = 'require';
+    }
+
+    switch (config.iceTransportPolicy) {
+      case 'all':
+      case 'relay':
+        break;
+      default:
+        config.iceTransportPolicy = 'all';
+        break;
+    }
+
+    switch (config.bundlePolicy) {
+      case 'balanced':
+      case 'max-compat':
+      case 'max-bundle':
+        break;
+      default:
+        config.bundlePolicy = 'balanced';
+        break;
+    }
+
+    config.iceServers = filterIceServers(config.iceServers || [], edgeVersion);
+
+    this._iceGatherers = [];
+    if (config.iceCandidatePoolSize) {
+      for (var i = config.iceCandidatePoolSize; i > 0; i--) {
+        this._iceGatherers = new window.RTCIceGatherer({
+          iceServers: config.iceServers,
+          gatherPolicy: config.iceTransportPolicy
+        });
+      }
+    } else {
+      config.iceCandidatePoolSize = 0;
+    }
+
+    this._config = config;
+
+    // per-track iceGathers, iceTransports, dtlsTransports, rtpSenders, ...
+    // everything that is needed to describe a SDP m-line.
+    this.transceivers = [];
+
+    this._sdpSessionId = SDPUtils.generateSessionId();
+    this._sdpSessionVersion = 0;
+
+    this._dtlsRole = undefined; // role for a=setup to use in answers.
+  };
+
+  RTCPeerConnection.prototype._emitGatheringStateChange = function() {
+    var event = new Event('icegatheringstatechange');
+    this.dispatchEvent(event);
+    if (typeof this.onicegatheringstatechange === 'function') {
+      this.onicegatheringstatechange(event);
+    }
+  };
+
+  RTCPeerConnection.prototype.getConfiguration = function() {
+    return this._config;
+  };
+
+  RTCPeerConnection.prototype.getLocalStreams = function() {
+    return this.localStreams;
+  };
+
+  RTCPeerConnection.prototype.getRemoteStreams = function() {
+    return this.remoteStreams;
+  };
+
+  // internal helper to create a transceiver object.
+  // (whih is not yet the same as the WebRTC 1.0 transceiver)
+  RTCPeerConnection.prototype._createTransceiver = function(kind) {
+    var hasBundleTransport = this.transceivers.length > 0;
+    var transceiver = {
+      track: null,
+      iceGatherer: null,
+      iceTransport: null,
+      dtlsTransport: null,
+      localCapabilities: null,
+      remoteCapabilities: null,
+      rtpSender: null,
+      rtpReceiver: null,
+      kind: kind,
+      mid: null,
+      sendEncodingParameters: null,
+      recvEncodingParameters: null,
+      stream: null,
+      wantReceive: true
+    };
+    if (this.usingBundle && hasBundleTransport) {
+      transceiver.iceTransport = this.transceivers[0].iceTransport;
+      transceiver.dtlsTransport = this.transceivers[0].dtlsTransport;
+    } else {
+      var transports = this._createIceAndDtlsTransports();
+      transceiver.iceTransport = transports.iceTransport;
+      transceiver.dtlsTransport = transports.dtlsTransport;
+    }
+    this.transceivers.push(transceiver);
+    return transceiver;
+  };
+
+  RTCPeerConnection.prototype.addTrack = function(track, stream) {
+    var transceiver;
+    for (var i = 0; i < this.transceivers.length; i++) {
+      if (!this.transceivers[i].track &&
+          this.transceivers[i].kind === track.kind) {
+        transceiver = this.transceivers[i];
+      }
+    }
+    if (!transceiver) {
+      transceiver = this._createTransceiver(track.kind);
+    }
+
+    this._maybeFireNegotiationNeeded();
+
+    if (this.localStreams.indexOf(stream) === -1) {
+      this.localStreams.push(stream);
+    }
+
+    transceiver.track = track;
+    transceiver.stream = stream;
+    transceiver.rtpSender = new window.RTCRtpSender(track,
+        transceiver.dtlsTransport);
+    return transceiver.rtpSender;
+  };
+
+  RTCPeerConnection.prototype.addStream = function(stream) {
+    var self = this;
+    if (edgeVersion >= 15025) {
+      stream.getTracks().forEach(function(track) {
+        self.addTrack(track, stream);
+      });
+    } else {
+      // Clone is necessary for local demos mostly, attaching directly
+      // to two different senders does not work (build 10547).
+      // Fixed in 15025 (or earlier)
+      var clonedStream = stream.clone();
+      stream.getTracks().forEach(function(track, idx) {
+        var clonedTrack = clonedStream.getTracks()[idx];
+        track.addEventListener('enabled', function(event) {
+          clonedTrack.enabled = event.enabled;
+        });
+      });
+      clonedStream.getTracks().forEach(function(track) {
+        self.addTrack(track, clonedStream);
+      });
+    }
+  };
+
+  RTCPeerConnection.prototype.removeStream = function(stream) {
+    var idx = this.localStreams.indexOf(stream);
+    if (idx > -1) {
+      this.localStreams.splice(idx, 1);
+      this._maybeFireNegotiationNeeded();
+    }
+  };
+
+  RTCPeerConnection.prototype.getSenders = function() {
+    return this.transceivers.filter(function(transceiver) {
+      return !!transceiver.rtpSender;
+    })
+    .map(function(transceiver) {
+      return transceiver.rtpSender;
+    });
+  };
+
+  RTCPeerConnection.prototype.getReceivers = function() {
+    return this.transceivers.filter(function(transceiver) {
+      return !!transceiver.rtpReceiver;
+    })
+    .map(function(transceiver) {
+      return transceiver.rtpReceiver;
+    });
+  };
+
+
+  RTCPeerConnection.prototype._createIceGatherer = function(sdpMLineIndex,
+      usingBundle) {
+    var self = this;
+    if (usingBundle && sdpMLineIndex > 0) {
+      return this.transceivers[0].iceGatherer;
+    } else if (this._iceGatherers.length) {
+      return this._iceGatherers.shift();
+    }
+    var iceGatherer = new window.RTCIceGatherer({
+      iceServers: this._config.iceServers,
+      gatherPolicy: this._config.iceTransportPolicy
+    });
+    Object.defineProperty(iceGatherer, 'state',
+        {value: 'new', writable: true}
+    );
+
+    this.transceivers[sdpMLineIndex].candidates = [];
+    this.transceivers[sdpMLineIndex].bufferCandidates = function(event) {
+      var end = !event.candidate || Object.keys(event.candidate).length === 0;
+      // polyfill since RTCIceGatherer.state is not implemented in
+      // Edge 10547 yet.
+      iceGatherer.state = end ? 'completed' : 'gathering';
+      if (self.transceivers[sdpMLineIndex].candidates !== null) {
+        self.transceivers[sdpMLineIndex].candidates.push(event.candidate);
+      }
+    };
+    iceGatherer.addEventListener('localcandidate',
+      this.transceivers[sdpMLineIndex].bufferCandidates);
+    return iceGatherer;
+  };
+
+  // start gathering from an RTCIceGatherer.
+  RTCPeerConnection.prototype._gather = function(mid, sdpMLineIndex) {
+    var self = this;
+    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
+    if (iceGatherer.onlocalcandidate) {
+      return;
+    }
+    var candidates = this.transceivers[sdpMLineIndex].candidates;
+    this.transceivers[sdpMLineIndex].candidates = null;
+    iceGatherer.removeEventListener('localcandidate',
+      this.transceivers[sdpMLineIndex].bufferCandidates);
+    iceGatherer.onlocalcandidate = function(evt) {
+      if (self.usingBundle && sdpMLineIndex > 0) {
+        // if we know that we use bundle we can drop candidates with
+        // ѕdpMLineIndex > 0. If we don't do this then our state gets
+        // confused since we dispose the extra ice gatherer.
+        return;
+      }
+      var event = new Event('icecandidate');
+      event.candidate = {sdpMid: mid, sdpMLineIndex: sdpMLineIndex};
+
+      var cand = evt.candidate;
+      // Edge emits an empty object for RTCIceCandidateComplete‥
+      var end = !cand || Object.keys(cand).length === 0;
+      if (end) {
+        // polyfill since RTCIceGatherer.state is not implemented in
+        // Edge 10547 yet.
+        if (iceGatherer.state === 'new' || iceGatherer.state === 'gathering') {
+          iceGatherer.state = 'completed';
+        }
+      } else {
+        if (iceGatherer.state === 'new') {
+          iceGatherer.state = 'gathering';
+        }
+        // RTCIceCandidate doesn't have a component, needs to be added
+        cand.component = 1;
+        event.candidate.candidate = SDPUtils.writeCandidate(cand);
+      }
+
+      // update local description.
+      var sections = SDPUtils.splitSections(self.localDescription.sdp);
+      if (!end) {
+        sections[event.candidate.sdpMLineIndex + 1] +=
+            'a=' + event.candidate.candidate + '\r\n';
+      } else {
+        sections[event.candidate.sdpMLineIndex + 1] +=
+            'a=end-of-candidates\r\n';
+      }
+      self.localDescription.sdp = sections.join('');
+      var complete = self.transceivers.every(function(transceiver) {
+        return transceiver.iceGatherer &&
+            transceiver.iceGatherer.state === 'completed';
+      });
+
+      if (self.iceGatheringState !== 'gathering') {
+        self.iceGatheringState = 'gathering';
+        self._emitGatheringStateChange();
+      }
+
+      // Emit candidate. Also emit null candidate when all gatherers are
+      // complete.
+      if (!end) {
+        self.dispatchEvent(event);
+        if (typeof self.onicecandidate === 'function') {
+          self.onicecandidate(event);
+        }
+      }
+      if (complete) {
+        self.dispatchEvent(new Event('icecandidate'));
+        if (typeof self.onicecandidate === 'function') {
+          self.onicecandidate(new Event('icecandidate'));
+        }
+        self.iceGatheringState = 'complete';
+        self._emitGatheringStateChange();
+      }
+    };
+
+    // emit already gathered candidates.
+    window.setTimeout(function() {
+      candidates.forEach(function(candidate) {
+        var e = new Event('RTCIceGatherEvent');
+        e.candidate = candidate;
+        iceGatherer.onlocalcandidate(e);
+      });
+    }, 0);
+  };
+
+  // Create ICE transport and DTLS transport.
+  RTCPeerConnection.prototype._createIceAndDtlsTransports = function() {
+    var self = this;
+    var iceTransport = new window.RTCIceTransport(null);
+    iceTransport.onicestatechange = function() {
+      self._updateConnectionState();
+    };
+
+    var dtlsTransport = new window.RTCDtlsTransport(iceTransport);
+    dtlsTransport.ondtlsstatechange = function() {
+      self._updateConnectionState();
+    };
+    dtlsTransport.onerror = function() {
+      // onerror does not set state to failed by itself.
+      Object.defineProperty(dtlsTransport, 'state',
+          {value: 'failed', writable: true});
+      self._updateConnectionState();
+    };
+
+    return {
+      iceTransport: iceTransport,
+      dtlsTransport: dtlsTransport
+    };
+  };
+
+  // Destroy ICE gatherer, ICE transport and DTLS transport.
+  // Without triggering the callbacks.
+  RTCPeerConnection.prototype._disposeIceAndDtlsTransports = function(
+      sdpMLineIndex) {
+    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
+    if (iceGatherer) {
+      delete iceGatherer.onlocalcandidate;
+      delete this.transceivers[sdpMLineIndex].iceGatherer;
+    }
+    var iceTransport = this.transceivers[sdpMLineIndex].iceTransport;
+    if (iceTransport) {
+      delete iceTransport.onicestatechange;
+      delete this.transceivers[sdpMLineIndex].iceTransport;
+    }
+    var dtlsTransport = this.transceivers[sdpMLineIndex].dtlsTransport;
+    if (dtlsTransport) {
+      delete dtlsTransport.ondtlsstatechange;
+      delete dtlsTransport.onerror;
+      delete this.transceivers[sdpMLineIndex].dtlsTransport;
+    }
+  };
+
+  // Start the RTP Sender and Receiver for a transceiver.
+  RTCPeerConnection.prototype._transceive = function(transceiver,
+      send, recv) {
+    var params = getCommonCapabilities(transceiver.localCapabilities,
+        transceiver.remoteCapabilities);
+    if (send && transceiver.rtpSender) {
+      params.encodings = transceiver.sendEncodingParameters;
+      params.rtcp = {
+        cname: SDPUtils.localCName,
+        compound: transceiver.rtcpParameters.compound
+      };
+      if (transceiver.recvEncodingParameters.length) {
+        params.rtcp.ssrc = transceiver.recvEncodingParameters[0].ssrc;
+      }
+      transceiver.rtpSender.send(params);
+    }
+    if (recv && transceiver.rtpReceiver && params.codecs.length > 0) {
+      // remove RTX field in Edge 14942
+      if (transceiver.kind === 'video'
+          && transceiver.recvEncodingParameters
+          && edgeVersion < 15019) {
+        transceiver.recvEncodingParameters.forEach(function(p) {
+          delete p.rtx;
+        });
+      }
+      params.encodings = transceiver.recvEncodingParameters;
+      params.rtcp = {
+        cname: transceiver.rtcpParameters.cname,
+        compound: transceiver.rtcpParameters.compound
+      };
+      if (transceiver.sendEncodingParameters.length) {
+        params.rtcp.ssrc = transceiver.sendEncodingParameters[0].ssrc;
+      }
+      transceiver.rtpReceiver.receive(params);
+    }
+  };
+
+  RTCPeerConnection.prototype.setLocalDescription = function(description) {
+    var self = this;
+    var args = arguments;
+
+    if (!isActionAllowedInSignalingState('setLocalDescription',
+        description.type, this.signalingState)) {
+      return new Promise(function(resolve, reject) {
+        var e = new Error('Can not set local ' + description.type +
+            ' in state ' + self.signalingState);
+        e.name = 'InvalidStateError';
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [e]);
+        }
+        reject(e);
+      });
+    }
+
+    var sections;
+    var sessionpart;
+    if (description.type === 'offer') {
+      // VERY limited support for SDP munging. Limited to:
+      // * changing the order of codecs
+      sections = SDPUtils.splitSections(description.sdp);
+      sessionpart = sections.shift();
+      sections.forEach(function(mediaSection, sdpMLineIndex) {
+        var caps = SDPUtils.parseRtpParameters(mediaSection);
+        self.transceivers[sdpMLineIndex].localCapabilities = caps;
+      });
+
+      this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+        self._gather(transceiver.mid, sdpMLineIndex);
+      });
+    } else if (description.type === 'answer') {
+      sections = SDPUtils.splitSections(self.remoteDescription.sdp);
+      sessionpart = sections.shift();
+      var isIceLite = SDPUtils.matchPrefix(sessionpart,
+          'a=ice-lite').length > 0;
+      sections.forEach(function(mediaSection, sdpMLineIndex) {
+        var transceiver = self.transceivers[sdpMLineIndex];
+        var iceGatherer = transceiver.iceGatherer;
+        var iceTransport = transceiver.iceTransport;
+        var dtlsTransport = transceiver.dtlsTransport;
+        var localCapabilities = transceiver.localCapabilities;
+        var remoteCapabilities = transceiver.remoteCapabilities;
+
+        // treat bundle-only as not-rejected.
+        var rejected = SDPUtils.isRejected(mediaSection) &&
+            !SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 1;
+
+        if (!rejected && !transceiver.isDatachannel) {
+          var remoteIceParameters = SDPUtils.getIceParameters(
+              mediaSection, sessionpart);
+          var remoteDtlsParameters = SDPUtils.getDtlsParameters(
+              mediaSection, sessionpart);
+          if (isIceLite) {
+            remoteDtlsParameters.role = 'server';
+          }
+
+          if (!self.usingBundle || sdpMLineIndex === 0) {
+            self._gather(transceiver.mid, sdpMLineIndex);
+            if (iceTransport.state === 'new') {
+              iceTransport.start(iceGatherer, remoteIceParameters,
+                  isIceLite ? 'controlling' : 'controlled');
+            }
+            if (dtlsTransport.state === 'new') {
+              dtlsTransport.start(remoteDtlsParameters);
+            }
+          }
+
+          // Calculate intersection of capabilities.
+          var params = getCommonCapabilities(localCapabilities,
+              remoteCapabilities);
+
+          // Start the RTCRtpSender. The RTCRtpReceiver for this
+          // transceiver has already been started in setRemoteDescription.
+          self._transceive(transceiver,
+              params.codecs.length > 0,
+              false);
+        }
+      });
+    }
+
+    this.localDescription = {
+      type: description.type,
+      sdp: description.sdp
+    };
+    switch (description.type) {
+      case 'offer':
+        this._updateSignalingState('have-local-offer');
+        break;
+      case 'answer':
+        this._updateSignalingState('stable');
+        break;
+      default:
+        throw new TypeError('unsupported type "' + description.type +
+            '"');
+    }
+
+    // If a success callback was provided, emit ICE candidates after it
+    // has been executed. Otherwise, emit callback after the Promise is
+    // resolved.
+    var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
+        arguments[1];
+    return new Promise(function(resolve) {
+      if (cb) {
+        cb.apply(null);
+      }
+      resolve();
+    });
+  };
+
+  RTCPeerConnection.prototype.setRemoteDescription = function(description) {
+    var self = this;
+    var args = arguments;
+
+    if (!isActionAllowedInSignalingState('setRemoteDescription',
+        description.type, this.signalingState)) {
+      return new Promise(function(resolve, reject) {
+        var e = new Error('Can not set remote ' + description.type +
+            ' in state ' + self.signalingState);
+        e.name = 'InvalidStateError';
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [e]);
+        }
+        reject(e);
+      });
+    }
+
+    var streams = {};
+    this.remoteStreams.forEach(function(stream) {
+      streams[stream.id] = stream;
+    });
+    var receiverList = [];
+    var sections = SDPUtils.splitSections(description.sdp);
+    var sessionpart = sections.shift();
+    var isIceLite = SDPUtils.matchPrefix(sessionpart,
+        'a=ice-lite').length > 0;
+    var usingBundle = SDPUtils.matchPrefix(sessionpart,
+        'a=group:BUNDLE ').length > 0;
+    this.usingBundle = usingBundle;
+    var iceOptions = SDPUtils.matchPrefix(sessionpart,
+        'a=ice-options:')[0];
+    if (iceOptions) {
+      this.canTrickleIceCandidates = iceOptions.substr(14).split(' ')
+          .indexOf('trickle') >= 0;
+    } else {
+      this.canTrickleIceCandidates = false;
+    }
+
+    sections.forEach(function(mediaSection, sdpMLineIndex) {
+      var lines = SDPUtils.splitLines(mediaSection);
+      var kind = SDPUtils.getKind(mediaSection);
+      // treat bundle-only as not-rejected.
+      var rejected = SDPUtils.isRejected(mediaSection) &&
+          !SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 1;
+      var protocol = lines[0].substr(2).split(' ')[2];
+
+      var direction = SDPUtils.getDirection(mediaSection, sessionpart);
+      var remoteMsid = SDPUtils.parseMsid(mediaSection);
+
+      var mid = SDPUtils.getMid(mediaSection) || SDPUtils.generateIdentifier();
+
+      // Reject datachannels which are not implemented yet.
+      if (kind === 'application' && protocol === 'DTLS/SCTP') {
+        self.transceivers[sdpMLineIndex] = {
+          mid: mid,
+          isDatachannel: true
+        };
+        return;
+      }
+
+      var transceiver;
+      var iceGatherer;
+      var iceTransport;
+      var dtlsTransport;
+      var rtpReceiver;
+      var sendEncodingParameters;
+      var recvEncodingParameters;
+      var localCapabilities;
+
+      var track;
+      // FIXME: ensure the mediaSection has rtcp-mux set.
+      var remoteCapabilities = SDPUtils.parseRtpParameters(mediaSection);
+      var remoteIceParameters;
+      var remoteDtlsParameters;
+      if (!rejected) {
+        remoteIceParameters = SDPUtils.getIceParameters(mediaSection,
+            sessionpart);
+        remoteDtlsParameters = SDPUtils.getDtlsParameters(mediaSection,
+            sessionpart);
+        remoteDtlsParameters.role = 'client';
+      }
+      recvEncodingParameters =
+          SDPUtils.parseRtpEncodingParameters(mediaSection);
+
+      var rtcpParameters = SDPUtils.parseRtcpParameters(mediaSection);
+
+      var isComplete = SDPUtils.matchPrefix(mediaSection,
+          'a=end-of-candidates', sessionpart).length > 0;
+      var cands = SDPUtils.matchPrefix(mediaSection, 'a=candidate:')
+          .map(function(cand) {
+            return SDPUtils.parseCandidate(cand);
+          })
+          .filter(function(cand) {
+            return cand.component === 1;
+          });
+
+      // Check if we can use BUNDLE and dispose transports.
+      if ((description.type === 'offer' || description.type === 'answer') &&
+          !rejected && usingBundle && sdpMLineIndex > 0 &&
+          self.transceivers[sdpMLineIndex]) {
+        self._disposeIceAndDtlsTransports(sdpMLineIndex);
+        self.transceivers[sdpMLineIndex].iceGatherer =
+            self.transceivers[0].iceGatherer;
+        self.transceivers[sdpMLineIndex].iceTransport =
+            self.transceivers[0].iceTransport;
+        self.transceivers[sdpMLineIndex].dtlsTransport =
+            self.transceivers[0].dtlsTransport;
+        if (self.transceivers[sdpMLineIndex].rtpSender) {
+          self.transceivers[sdpMLineIndex].rtpSender.setTransport(
+              self.transceivers[0].dtlsTransport);
+        }
+        if (self.transceivers[sdpMLineIndex].rtpReceiver) {
+          self.transceivers[sdpMLineIndex].rtpReceiver.setTransport(
+              self.transceivers[0].dtlsTransport);
+        }
+      }
+      if (description.type === 'offer' && !rejected) {
+        transceiver = self.transceivers[sdpMLineIndex] ||
+            self._createTransceiver(kind);
+        transceiver.mid = mid;
+
+        if (!transceiver.iceGatherer) {
+          transceiver.iceGatherer = self._createIceGatherer(sdpMLineIndex,
+              usingBundle);
+        }
+
+        if (cands.length && transceiver.iceTransport.state === 'new') {
+          if (isComplete && (!usingBundle || sdpMLineIndex === 0)) {
+            transceiver.iceTransport.setRemoteCandidates(cands);
+          } else {
+            cands.forEach(function(candidate) {
+              maybeAddCandidate(transceiver.iceTransport, candidate);
+            });
+          }
+        }
+
+        localCapabilities = window.RTCRtpReceiver.getCapabilities(kind);
+
+        // filter RTX until additional stuff needed for RTX is implemented
+        // in adapter.js
+        if (edgeVersion < 15019) {
+          localCapabilities.codecs = localCapabilities.codecs.filter(
+              function(codec) {
+                return codec.name !== 'rtx';
+              });
+        }
+
+        sendEncodingParameters = transceiver.sendEncodingParameters || [{
+          ssrc: (2 * sdpMLineIndex + 2) * 1001
+        }];
+
+        var isNewTrack = false;
+        if (direction === 'sendrecv' || direction === 'sendonly') {
+          isNewTrack = !transceiver.rtpReceiver;
+          rtpReceiver = transceiver.rtpReceiver ||
+              new window.RTCRtpReceiver(transceiver.dtlsTransport, kind);
+
+          if (isNewTrack) {
+            var stream;
+            track = rtpReceiver.track;
+            // FIXME: does not work with Plan B.
+            if (remoteMsid) {
+              if (!streams[remoteMsid.stream]) {
+                streams[remoteMsid.stream] = new window.MediaStream();
+                Object.defineProperty(streams[remoteMsid.stream], 'id', {
+                  get: function() {
+                    return remoteMsid.stream;
+                  }
+                });
+              }
+              Object.defineProperty(track, 'id', {
+                get: function() {
+                  return remoteMsid.track;
+                }
+              });
+              stream = streams[remoteMsid.stream];
+            } else {
+              if (!streams.default) {
+                streams.default = new window.MediaStream();
+              }
+              stream = streams.default;
+            }
+            stream.addTrack(track);
+            receiverList.push([track, rtpReceiver, stream]);
+          }
+        }
+
+        transceiver.localCapabilities = localCapabilities;
+        transceiver.remoteCapabilities = remoteCapabilities;
+        transceiver.rtpReceiver = rtpReceiver;
+        transceiver.rtcpParameters = rtcpParameters;
+        transceiver.sendEncodingParameters = sendEncodingParameters;
+        transceiver.recvEncodingParameters = recvEncodingParameters;
+
+        // Start the RTCRtpReceiver now. The RTPSender is started in
+        // setLocalDescription.
+        self._transceive(self.transceivers[sdpMLineIndex],
+            false,
+            isNewTrack);
+      } else if (description.type === 'answer' && !rejected) {
+        transceiver = self.transceivers[sdpMLineIndex];
+        iceGatherer = transceiver.iceGatherer;
+        iceTransport = transceiver.iceTransport;
+        dtlsTransport = transceiver.dtlsTransport;
+        rtpReceiver = transceiver.rtpReceiver;
+        sendEncodingParameters = transceiver.sendEncodingParameters;
+        localCapabilities = transceiver.localCapabilities;
+
+        self.transceivers[sdpMLineIndex].recvEncodingParameters =
+            recvEncodingParameters;
+        self.transceivers[sdpMLineIndex].remoteCapabilities =
+            remoteCapabilities;
+        self.transceivers[sdpMLineIndex].rtcpParameters = rtcpParameters;
+
+        if (cands.length && iceTransport.state === 'new') {
+          if ((isIceLite || isComplete) &&
+              (!usingBundle || sdpMLineIndex === 0)) {
+            iceTransport.setRemoteCandidates(cands);
+          } else {
+            cands.forEach(function(candidate) {
+              maybeAddCandidate(transceiver.iceTransport, candidate);
+            });
+          }
+        }
+
+        if (!usingBundle || sdpMLineIndex === 0) {
+          if (iceTransport.state === 'new') {
+            iceTransport.start(iceGatherer, remoteIceParameters,
+                'controlling');
+          }
+          if (dtlsTransport.state === 'new') {
+            dtlsTransport.start(remoteDtlsParameters);
+          }
+        }
+
+        self._transceive(transceiver,
+            direction === 'sendrecv' || direction === 'recvonly',
+            direction === 'sendrecv' || direction === 'sendonly');
+
+        if (rtpReceiver &&
+            (direction === 'sendrecv' || direction === 'sendonly')) {
+          track = rtpReceiver.track;
+          if (remoteMsid) {
+            if (!streams[remoteMsid.stream]) {
+              streams[remoteMsid.stream] = new window.MediaStream();
+            }
+            streams[remoteMsid.stream].addTrack(track);
+            receiverList.push([track, rtpReceiver, streams[remoteMsid.stream]]);
+          } else {
+            if (!streams.default) {
+              streams.default = new window.MediaStream();
+            }
+            streams.default.addTrack(track);
+            receiverList.push([track, rtpReceiver, streams.default]);
+          }
+        } else {
+          // FIXME: actually the receiver should be created later.
+          delete transceiver.rtpReceiver;
+        }
+      }
+    });
+
+    if (this._dtlsRole === undefined) {
+      this._dtlsRole = description.type === 'offer' ? 'active' : 'passive';
+    }
+
+    this.remoteDescription = {
+      type: description.type,
+      sdp: description.sdp
+    };
+    switch (description.type) {
+      case 'offer':
+        this._updateSignalingState('have-remote-offer');
+        break;
+      case 'answer':
+        this._updateSignalingState('stable');
+        break;
+      default:
+        throw new TypeError('unsupported type "' + description.type +
+            '"');
+    }
+    Object.keys(streams).forEach(function(sid) {
+      var stream = streams[sid];
+      if (stream.getTracks().length) {
+        if (self.remoteStreams.indexOf(stream) === -1) {
+          self.remoteStreams.push(stream);
+          var event = new Event('addstream');
+          event.stream = stream;
+          window.setTimeout(function() {
+            self.dispatchEvent(event);
+            if (typeof self.onaddstream === 'function') {
+              self.onaddstream(event);
+            }
+          });
+        }
+
+        receiverList.forEach(function(item) {
+          var track = item[0];
+          var receiver = item[1];
+          if (stream.id !== item[2].id) {
+            return;
+          }
+          var trackEvent = new Event('track');
+          trackEvent.track = track;
+          trackEvent.receiver = receiver;
+          trackEvent.transceiver = {receiver: receiver};
+          trackEvent.streams = [stream];
+          window.setTimeout(function() {
+            self.dispatchEvent(trackEvent);
+            if (typeof self.ontrack === 'function') {
+              self.ontrack(trackEvent);
+            }
+          });
+        });
+      }
+    });
+
+    // check whether addIceCandidate({}) was called within four seconds after
+    // setRemoteDescription.
+    window.setTimeout(function() {
+      if (!(self && self.transceivers)) {
+        return;
+      }
+      self.transceivers.forEach(function(transceiver) {
+        if (transceiver.iceTransport &&
+            transceiver.iceTransport.state === 'new' &&
+            transceiver.iceTransport.getRemoteCandidates().length > 0) {
+          console.warn('Timeout for addRemoteCandidate. Consider sending ' +
+              'an end-of-candidates notification');
+          transceiver.iceTransport.addRemoteCandidate({});
+        }
+      });
+    }, 4000);
+
+    return new Promise(function(resolve) {
+      if (args.length > 1 && typeof args[1] === 'function') {
+        args[1].apply(null);
+      }
+      resolve();
+    });
+  };
+
+  RTCPeerConnection.prototype.close = function() {
+    this.transceivers.forEach(function(transceiver) {
+      /* not yet
+      if (transceiver.iceGatherer) {
+        transceiver.iceGatherer.close();
+      }
+      */
+      if (transceiver.iceTransport) {
+        transceiver.iceTransport.stop();
+      }
+      if (transceiver.dtlsTransport) {
+        transceiver.dtlsTransport.stop();
+      }
+      if (transceiver.rtpSender) {
+        transceiver.rtpSender.stop();
+      }
+      if (transceiver.rtpReceiver) {
+        transceiver.rtpReceiver.stop();
+      }
+    });
+    // FIXME: clean up tracks, local streams, remote streams, etc
+    this._updateSignalingState('closed');
+  };
+
+  // Update the signaling state.
+  RTCPeerConnection.prototype._updateSignalingState = function(newState) {
+    this.signalingState = newState;
+    var event = new Event('signalingstatechange');
+    this.dispatchEvent(event);
+    if (typeof this.onsignalingstatechange === 'function') {
+      this.onsignalingstatechange(event);
+    }
+  };
+
+  // Determine whether to fire the negotiationneeded event.
+  RTCPeerConnection.prototype._maybeFireNegotiationNeeded = function() {
+    var self = this;
+    if (this.signalingState !== 'stable' || this.needNegotiation === true) {
+      return;
+    }
+    this.needNegotiation = true;
+    window.setTimeout(function() {
+      if (self.needNegotiation === false) {
+        return;
+      }
+      self.needNegotiation = false;
+      var event = new Event('negotiationneeded');
+      self.dispatchEvent(event);
+      if (typeof self.onnegotiationneeded === 'function') {
+        self.onnegotiationneeded(event);
+      }
+    }, 0);
+  };
+
+  // Update the connection state.
+  RTCPeerConnection.prototype._updateConnectionState = function() {
+    var newState;
+    var states = {
+      'new': 0,
+      closed: 0,
+      connecting: 0,
+      checking: 0,
+      connected: 0,
+      completed: 0,
+      disconnected: 0,
+      failed: 0
+    };
+    this.transceivers.forEach(function(transceiver) {
+      states[transceiver.iceTransport.state]++;
+      states[transceiver.dtlsTransport.state]++;
+    });
+    // ICETransport.completed and connected are the same for this purpose.
+    states.connected += states.completed;
+
+    newState = 'new';
+    if (states.failed > 0) {
+      newState = 'failed';
+    } else if (states.connecting > 0 || states.checking > 0) {
+      newState = 'connecting';
+    } else if (states.disconnected > 0) {
+      newState = 'disconnected';
+    } else if (states.new > 0) {
+      newState = 'new';
+    } else if (states.connected > 0 || states.completed > 0) {
+      newState = 'connected';
+    }
+
+    if (newState !== this.iceConnectionState) {
+      this.iceConnectionState = newState;
+      var event = new Event('iceconnectionstatechange');
+      this.dispatchEvent(event);
+      if (typeof this.oniceconnectionstatechange === 'function') {
+        this.oniceconnectionstatechange(event);
+      }
+    }
+  };
+
+  RTCPeerConnection.prototype.createOffer = function() {
+    var self = this;
+    var args = arguments;
+
+    var offerOptions;
+    if (arguments.length === 1 && typeof arguments[0] !== 'function') {
+      offerOptions = arguments[0];
+    } else if (arguments.length === 3) {
+      offerOptions = arguments[2];
+    }
+
+    var numAudioTracks = this.transceivers.filter(function(t) {
+      return t.kind === 'audio';
+    }).length;
+    var numVideoTracks = this.transceivers.filter(function(t) {
+      return t.kind === 'video';
+    }).length;
+
+    // Determine number of audio and video tracks we need to send/recv.
+    if (offerOptions) {
+      // Reject Chrome legacy constraints.
+      if (offerOptions.mandatory || offerOptions.optional) {
+        throw new TypeError(
+            'Legacy mandatory/optional constraints not supported.');
+      }
+      if (offerOptions.offerToReceiveAudio !== undefined) {
+        if (offerOptions.offerToReceiveAudio === true) {
+          numAudioTracks = 1;
+        } else if (offerOptions.offerToReceiveAudio === false) {
+          numAudioTracks = 0;
+        } else {
+          numAudioTracks = offerOptions.offerToReceiveAudio;
+        }
+      }
+      if (offerOptions.offerToReceiveVideo !== undefined) {
+        if (offerOptions.offerToReceiveVideo === true) {
+          numVideoTracks = 1;
+        } else if (offerOptions.offerToReceiveVideo === false) {
+          numVideoTracks = 0;
+        } else {
+          numVideoTracks = offerOptions.offerToReceiveVideo;
+        }
+      }
+    }
+
+    this.transceivers.forEach(function(transceiver) {
+      if (transceiver.kind === 'audio') {
+        numAudioTracks--;
+        if (numAudioTracks < 0) {
+          transceiver.wantReceive = false;
+        }
+      } else if (transceiver.kind === 'video') {
+        numVideoTracks--;
+        if (numVideoTracks < 0) {
+          transceiver.wantReceive = false;
+        }
+      }
+    });
+
+    // Create M-lines for recvonly streams.
+    while (numAudioTracks > 0 || numVideoTracks > 0) {
+      if (numAudioTracks > 0) {
+        this._createTransceiver('audio');
+        numAudioTracks--;
+      }
+      if (numVideoTracks > 0) {
+        this._createTransceiver('video');
+        numVideoTracks--;
+      }
+    }
+
+    var sdp = SDPUtils.writeSessionBoilerplate(this._sdpSessionId,
+        this._sdpSessionVersion++);
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      // For each track, create an ice gatherer, ice transport,
+      // dtls transport, potentially rtpsender and rtpreceiver.
+      var track = transceiver.track;
+      var kind = transceiver.kind;
+      var mid = SDPUtils.generateIdentifier();
+      transceiver.mid = mid;
+
+      if (!transceiver.iceGatherer) {
+        transceiver.iceGatherer = self._createIceGatherer(sdpMLineIndex,
+            self.usingBundle);
+      }
+
+      var localCapabilities = window.RTCRtpSender.getCapabilities(kind);
+      // filter RTX until additional stuff needed for RTX is implemented
+      // in adapter.js
+      if (edgeVersion < 15019) {
+        localCapabilities.codecs = localCapabilities.codecs.filter(
+            function(codec) {
+              return codec.name !== 'rtx';
+            });
+      }
+      localCapabilities.codecs.forEach(function(codec) {
+        // work around https://bugs.chromium.org/p/webrtc/issues/detail?id=6552
+        // by adding level-asymmetry-allowed=1
+        if (codec.name === 'H264' &&
+            codec.parameters['level-asymmetry-allowed'] === undefined) {
+          codec.parameters['level-asymmetry-allowed'] = '1';
+        }
+      });
+
+      // generate an ssrc now, to be used later in rtpSender.send
+      var sendEncodingParameters = transceiver.sendEncodingParameters || [{
+        ssrc: (2 * sdpMLineIndex + 1) * 1001
+      }];
+      if (track) {
+        // add RTX
+        if (edgeVersion >= 15019 && kind === 'video' &&
+            !sendEncodingParameters[0].rtx) {
+          sendEncodingParameters[0].rtx = {
+            ssrc: sendEncodingParameters[0].ssrc + 1
+          };
+        }
+      }
+
+      if (transceiver.wantReceive) {
+        transceiver.rtpReceiver = new window.RTCRtpReceiver(
+            transceiver.dtlsTransport, kind);
+      }
+
+      transceiver.localCapabilities = localCapabilities;
+      transceiver.sendEncodingParameters = sendEncodingParameters;
+    });
+
+    // always offer BUNDLE and dispose on return if not supported.
+    if (this._config.bundlePolicy !== 'max-compat') {
+      sdp += 'a=group:BUNDLE ' + this.transceivers.map(function(t) {
+        return t.mid;
+      }).join(' ') + '\r\n';
+    }
+    sdp += 'a=ice-options:trickle\r\n';
+
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      sdp += writeMediaSection(transceiver, transceiver.localCapabilities,
+          'offer', transceiver.stream, self._dtlsRole);
+      sdp += 'a=rtcp-rsize\r\n';
+
+      if (transceiver.iceGatherer && self.iceGatheringState !== 'new' &&
+          (sdpMLineIndex === 0 || !self.usingBundle)) {
+        transceiver.iceGatherer.getLocalCandidates().forEach(function(cand) {
+          cand.component = 1;
+          sdp += 'a=' + SDPUtils.writeCandidate(cand) + '\r\n';
+        });
+
+        if (transceiver.iceGatherer.state === 'completed') {
+          sdp += 'a=end-of-candidates\r\n';
+        }
+      }
+    });
+
+    var desc = new window.RTCSessionDescription({
+      type: 'offer',
+      sdp: sdp
+    });
+    return new Promise(function(resolve) {
+      if (args.length > 0 && typeof args[0] === 'function') {
+        args[0].apply(null, [desc]);
+        resolve();
+        return;
+      }
+      resolve(desc);
+    });
+  };
+
+  RTCPeerConnection.prototype.createAnswer = function() {
+    var self = this;
+    var args = arguments;
+
+    var sdp = SDPUtils.writeSessionBoilerplate(this._sdpSessionId,
+        this._sdpSessionVersion++);
+    if (this.usingBundle) {
+      sdp += 'a=group:BUNDLE ' + this.transceivers.map(function(t) {
+        return t.mid;
+      }).join(' ') + '\r\n';
+    }
+    var mediaSectionsInOffer = SDPUtils.splitSections(
+        this.remoteDescription.sdp).length - 1;
+    this.transceivers.forEach(function(transceiver, sdpMLineIndex) {
+      if (sdpMLineIndex + 1 > mediaSectionsInOffer) {
+        return;
+      }
+      if (transceiver.isDatachannel) {
+        sdp += 'm=application 0 DTLS/SCTP 5000\r\n' +
+            'c=IN IP4 0.0.0.0\r\n' +
+            'a=mid:' + transceiver.mid + '\r\n';
+        return;
+      }
+
+      // FIXME: look at direction.
+      if (transceiver.stream) {
+        var localTrack;
+        if (transceiver.kind === 'audio') {
+          localTrack = transceiver.stream.getAudioTracks()[0];
+        } else if (transceiver.kind === 'video') {
+          localTrack = transceiver.stream.getVideoTracks()[0];
+        }
+        if (localTrack) {
+          // add RTX
+          if (edgeVersion >= 15019 && transceiver.kind === 'video' &&
+              !transceiver.sendEncodingParameters[0].rtx) {
+            transceiver.sendEncodingParameters[0].rtx = {
+              ssrc: transceiver.sendEncodingParameters[0].ssrc + 1
+            };
+          }
+        }
+      }
+
+      // Calculate intersection of capabilities.
+      var commonCapabilities = getCommonCapabilities(
+          transceiver.localCapabilities,
+          transceiver.remoteCapabilities);
+
+      var hasRtx = commonCapabilities.codecs.filter(function(c) {
+        return c.name.toLowerCase() === 'rtx';
+      }).length;
+      if (!hasRtx && transceiver.sendEncodingParameters[0].rtx) {
+        delete transceiver.sendEncodingParameters[0].rtx;
+      }
+
+      sdp += writeMediaSection(transceiver, commonCapabilities,
+          'answer', transceiver.stream, self._dtlsRole);
+      if (transceiver.rtcpParameters &&
+          transceiver.rtcpParameters.reducedSize) {
+        sdp += 'a=rtcp-rsize\r\n';
+      }
+    });
+
+    var desc = new window.RTCSessionDescription({
+      type: 'answer',
+      sdp: sdp
+    });
+    return new Promise(function(resolve) {
+      if (args.length > 0 && typeof args[0] === 'function') {
+        args[0].apply(null, [desc]);
+        resolve();
+        return;
+      }
+      resolve(desc);
+    });
+  };
+
+  RTCPeerConnection.prototype.addIceCandidate = function(candidate) {
+    var err;
+    var sections;
+    if (!candidate || candidate.candidate === '') {
+      for (var j = 0; j < this.transceivers.length; j++) {
+        if (this.transceivers[j].isDatachannel) {
+          continue;
+        }
+        this.transceivers[j].iceTransport.addRemoteCandidate({});
+        sections = SDPUtils.splitSections(this.remoteDescription.sdp);
+        sections[j + 1] += 'a=end-of-candidates\r\n';
+        this.remoteDescription.sdp = sections.join('');
+        if (this.usingBundle) {
+          break;
+        }
+      }
+    } else if (!(candidate.sdpMLineIndex !== undefined || candidate.sdpMid)) {
+      throw new TypeError('sdpMLineIndex or sdpMid required');
+    } else if (!this.remoteDescription) {
+      err = new Error('Can not add ICE candidate without ' +
+          'a remote description');
+      err.name = 'InvalidStateError';
+    } else {
+      var sdpMLineIndex = candidate.sdpMLineIndex;
+      if (candidate.sdpMid) {
+        for (var i = 0; i < this.transceivers.length; i++) {
+          if (this.transceivers[i].mid === candidate.sdpMid) {
+            sdpMLineIndex = i;
+            break;
+          }
+        }
+      }
+      var transceiver = this.transceivers[sdpMLineIndex];
+      if (transceiver) {
+        if (transceiver.isDatachannel) {
+          return Promise.resolve();
+        }
+        var cand = Object.keys(candidate.candidate).length > 0 ?
+            SDPUtils.parseCandidate(candidate.candidate) : {};
+        // Ignore Chrome's invalid candidates since Edge does not like them.
+        if (cand.protocol === 'tcp' && (cand.port === 0 || cand.port === 9)) {
+          return Promise.resolve();
+        }
+        // Ignore RTCP candidates, we assume RTCP-MUX.
+        if (cand.component && cand.component !== 1) {
+          return Promise.resolve();
+        }
+        // when using bundle, avoid adding candidates to the wrong
+        // ice transport. And avoid adding candidates added in the SDP.
+        if (sdpMLineIndex === 0 || (sdpMLineIndex > 0 &&
+            transceiver.iceTransport !== this.transceivers[0].iceTransport)) {
+          if (!maybeAddCandidate(transceiver.iceTransport, cand)) {
+            err = new Error('Can not add ICE candidate');
+            err.name = 'OperationError';
+          }
+        }
+
+        if (!err) {
+          // update the remoteDescription.
+          var candidateString = candidate.candidate.trim();
+          if (candidateString.indexOf('a=') === 0) {
+            candidateString = candidateString.substr(2);
+          }
+          sections = SDPUtils.splitSections(this.remoteDescription.sdp);
+          sections[sdpMLineIndex + 1] += 'a=' +
+              (cand.type ? candidateString : 'end-of-candidates')
+              + '\r\n';
+          this.remoteDescription.sdp = sections.join('');
+        }
+      } else {
+        err = new Error('Can not add ICE candidate');
+        err.name = 'OperationError';
+      }
+    }
+    var args = arguments;
+    return new Promise(function(resolve, reject) {
+      if (err) {
+        if (args.length > 2 && typeof args[2] === 'function') {
+          args[2].apply(null, [err]);
+        }
+        reject(err);
+      } else {
+        if (args.length > 1 && typeof args[1] === 'function') {
+          args[1].apply(null);
+        }
+        resolve();
+      }
+    });
+  };
+
+  RTCPeerConnection.prototype.getStats = function() {
+    var promises = [];
+    this.transceivers.forEach(function(transceiver) {
+      ['rtpSender', 'rtpReceiver', 'iceGatherer', 'iceTransport',
+          'dtlsTransport'].forEach(function(method) {
+            if (transceiver[method]) {
+              promises.push(transceiver[method].getStats());
+            }
+          });
+    });
+    var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
+        arguments[1];
+    var fixStatsType = function(stat) {
+      return {
+        inboundrtp: 'inbound-rtp',
+        outboundrtp: 'outbound-rtp',
+        candidatepair: 'candidate-pair',
+        localcandidate: 'local-candidate',
+        remotecandidate: 'remote-candidate'
+      }[stat.type] || stat.type;
+    };
+    return new Promise(function(resolve) {
+      // shim getStats with maplike support
+      var results = new Map();
+      Promise.all(promises).then(function(res) {
+        res.forEach(function(result) {
+          Object.keys(result).forEach(function(id) {
+            result[id].type = fixStatsType(result[id]);
+            results.set(id, result[id]);
+          });
+        });
+        if (cb) {
+          cb.apply(null, results);
+        }
+        resolve(results);
+      });
+    });
+  };
+  return RTCPeerConnection;
+};
+
+},{"sdp":2}],2:[function(require,module,exports){
+ /* eslint-env node */
+'use strict';
+
+// SDP helpers.
+var SDPUtils = {};
+
+// Generate an alphanumeric identifier for cname or mids.
+// TODO: use UUIDs instead? https://gist.github.com/jed/982883
+SDPUtils.generateIdentifier = function() {
+  return Math.random().toString(36).substr(2, 10);
+};
+
+// The RTCP CNAME used by all peerconnections from the same JS.
+SDPUtils.localCName = SDPUtils.generateIdentifier();
+
+// Splits SDP into lines, dealing with both CRLF and LF.
+SDPUtils.splitLines = function(blob) {
+  return blob.trim().split('\n').map(function(line) {
+    return line.trim();
+  });
+};
+// Splits SDP into sessionpart and mediasections. Ensures CRLF.
+SDPUtils.splitSections = function(blob) {
+  var parts = blob.split('\nm=');
+  return parts.map(function(part, index) {
+    return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
+  });
+};
+
+// Returns lines that start with a certain prefix.
+SDPUtils.matchPrefix = function(blob, prefix) {
+  return SDPUtils.splitLines(blob).filter(function(line) {
+    return line.indexOf(prefix) === 0;
+  });
+};
+
+// Parses an ICE candidate line. Sample input:
+// candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8
+// rport 55996"
+SDPUtils.parseCandidate = function(line) {
+  var parts;
+  // Parse both variants.
+  if (line.indexOf('a=candidate:') === 0) {
+    parts = line.substring(12).split(' ');
+  } else {
+    parts = line.substring(10).split(' ');
+  }
+
+  var candidate = {
+    foundation: parts[0],
+    component: parseInt(parts[1], 10),
+    protocol: parts[2].toLowerCase(),
+    priority: parseInt(parts[3], 10),
+    ip: parts[4],
+    port: parseInt(parts[5], 10),
+    // skip parts[6] == 'typ'
+    type: parts[7]
+  };
+
+  for (var i = 8; i < parts.length; i += 2) {
+    switch (parts[i]) {
+      case 'raddr':
+        candidate.relatedAddress = parts[i + 1];
+        break;
+      case 'rport':
+        candidate.relatedPort = parseInt(parts[i + 1], 10);
+        break;
+      case 'tcptype':
+        candidate.tcpType = parts[i + 1];
+        break;
+      case 'ufrag':
+        candidate.ufrag = parts[i + 1]; // for backward compability.
+        candidate.usernameFragment = parts[i + 1];
+        break;
+      default: // extension handling, in particular ufrag
+        candidate[parts[i]] = parts[i + 1];
+        break;
+    }
+  }
+  return candidate;
+};
+
+// Translates a candidate object into SDP candidate attribute.
+SDPUtils.writeCandidate = function(candidate) {
+  var sdp = [];
+  sdp.push(candidate.foundation);
+  sdp.push(candidate.component);
+  sdp.push(candidate.protocol.toUpperCase());
+  sdp.push(candidate.priority);
+  sdp.push(candidate.ip);
+  sdp.push(candidate.port);
+
+  var type = candidate.type;
+  sdp.push('typ');
+  sdp.push(type);
+  if (type !== 'host' && candidate.relatedAddress &&
+      candidate.relatedPort) {
+    sdp.push('raddr');
+    sdp.push(candidate.relatedAddress); // was: relAddr
+    sdp.push('rport');
+    sdp.push(candidate.relatedPort); // was: relPort
+  }
+  if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
+    sdp.push('tcptype');
+    sdp.push(candidate.tcpType);
+  }
+  if (candidate.ufrag) {
+    sdp.push('ufrag');
+    sdp.push(candidate.ufrag);
+  }
+  return 'candidate:' + sdp.join(' ');
+};
+
+// Parses an ice-options line, returns an array of option tags.
+// a=ice-options:foo bar
+SDPUtils.parseIceOptions = function(line) {
+  return line.substr(14).split(' ');
+}
+
+// Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
+// a=rtpmap:111 opus/48000/2
+SDPUtils.parseRtpMap = function(line) {
+  var parts = line.substr(9).split(' ');
+  var parsed = {
+    payloadType: parseInt(parts.shift(), 10) // was: id
+  };
+
+  parts = parts[0].split('/');
+
+  parsed.name = parts[0];
+  parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
+  // was: channels
+  parsed.numChannels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
+  return parsed;
+};
+
+// Generate an a=rtpmap line from RTCRtpCodecCapability or
+// RTCRtpCodecParameters.
+SDPUtils.writeRtpMap = function(codec) {
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
+      (codec.numChannels !== 1 ? '/' + codec.numChannels : '') + '\r\n';
+};
+
+// Parses an a=extmap line (headerextension from RFC 5285). Sample input:
+// a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
+// a=extmap:2/sendonly urn:ietf:params:rtp-hdrext:toffset
+SDPUtils.parseExtmap = function(line) {
+  var parts = line.substr(9).split(' ');
+  return {
+    id: parseInt(parts[0], 10),
+    direction: parts[0].indexOf('/') > 0 ? parts[0].split('/')[1] : 'sendrecv',
+    uri: parts[1]
+  };
+};
+
+// Generates a=extmap line from RTCRtpHeaderExtensionParameters or
+// RTCRtpHeaderExtension.
+SDPUtils.writeExtmap = function(headerExtension) {
+  return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
+      (headerExtension.direction && headerExtension.direction !== 'sendrecv'
+          ? '/' + headerExtension.direction
+          : '') +
+      ' ' + headerExtension.uri + '\r\n';
+};
+
+// Parses an ftmp line, returns dictionary. Sample input:
+// a=fmtp:96 vbr=on;cng=on
+// Also deals with vbr=on; cng=on
+SDPUtils.parseFmtp = function(line) {
+  var parsed = {};
+  var kv;
+  var parts = line.substr(line.indexOf(' ') + 1).split(';');
+  for (var j = 0; j < parts.length; j++) {
+    kv = parts[j].trim().split('=');
+    parsed[kv[0].trim()] = kv[1];
+  }
+  return parsed;
+};
+
+// Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeFmtp = function(codec) {
+  var line = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.parameters && Object.keys(codec.parameters).length) {
+    var params = [];
+    Object.keys(codec.parameters).forEach(function(param) {
+      params.push(param + '=' + codec.parameters[param]);
+    });
+    line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
+  }
+  return line;
+};
+
+// Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
+// a=rtcp-fb:98 nack rpsi
+SDPUtils.parseRtcpFb = function(line) {
+  var parts = line.substr(line.indexOf(' ') + 1).split(' ');
+  return {
+    type: parts.shift(),
+    parameter: parts.join(' ')
+  };
+};
+// Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
+SDPUtils.writeRtcpFb = function(codec) {
+  var lines = '';
+  var pt = codec.payloadType;
+  if (codec.preferredPayloadType !== undefined) {
+    pt = codec.preferredPayloadType;
+  }
+  if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
+    // FIXME: special handling for trr-int?
+    codec.rtcpFeedback.forEach(function(fb) {
+      lines += 'a=rtcp-fb:' + pt + ' ' + fb.type +
+      (fb.parameter && fb.parameter.length ? ' ' + fb.parameter : '') +
+          '\r\n';
+    });
+  }
+  return lines;
+};
+
+// Parses an RFC 5576 ssrc media attribute. Sample input:
+// a=ssrc:3735928559 cname:something
+SDPUtils.parseSsrcMedia = function(line) {
+  var sp = line.indexOf(' ');
+  var parts = {
+    ssrc: parseInt(line.substr(7, sp - 7), 10)
+  };
+  var colon = line.indexOf(':', sp);
+  if (colon > -1) {
+    parts.attribute = line.substr(sp + 1, colon - sp - 1);
+    parts.value = line.substr(colon + 1);
+  } else {
+    parts.attribute = line.substr(sp + 1);
+  }
+  return parts;
+};
+
+// Extracts the MID (RFC 5888) from a media section.
+// returns the MID or undefined if no mid line was found.
+SDPUtils.getMid = function(mediaSection) {
+  var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0];
+  if (mid) {
+    return mid.substr(6);
+  }
+}
+
+SDPUtils.parseFingerprint = function(line) {
+  var parts = line.substr(14).split(' ');
+  return {
+    algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
+    value: parts[1]
+  };
+};
+
+// Extracts DTLS parameters from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the fingerprint line as input. See also getIceParameters.
+SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.matchPrefix(mediaSection + sessionpart,
+      'a=fingerprint:');
+  // Note: a=setup line is ignored since we use the 'auto' role.
+  // Note2: 'algorithm' is not case sensitive except in Edge.
+  return {
+    role: 'auto',
+    fingerprints: lines.map(SDPUtils.parseFingerprint)
+  };
+};
+
+// Serializes DTLS parameters to SDP.
+SDPUtils.writeDtlsParameters = function(params, setupType) {
+  var sdp = 'a=setup:' + setupType + '\r\n';
+  params.fingerprints.forEach(function(fp) {
+    sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
+  });
+  return sdp;
+};
+// Parses ICE information from SDP media section or sessionpart.
+// FIXME: for consistency with other functions this should only
+//   get the ice-ufrag and ice-pwd lines as input.
+SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  // Search in session part, too.
+  lines = lines.concat(SDPUtils.splitLines(sessionpart));
+  var iceParameters = {
+    usernameFragment: lines.filter(function(line) {
+      return line.indexOf('a=ice-ufrag:') === 0;
+    })[0].substr(12),
+    password: lines.filter(function(line) {
+      return line.indexOf('a=ice-pwd:') === 0;
+    })[0].substr(10)
+  };
+  return iceParameters;
+};
+
+// Serializes ICE parameters to SDP.
+SDPUtils.writeIceParameters = function(params) {
+  return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
+      'a=ice-pwd:' + params.password + '\r\n';
+};
+
+// Parses the SDP media section and returns RTCRtpParameters.
+SDPUtils.parseRtpParameters = function(mediaSection) {
+  var description = {
+    codecs: [],
+    headerExtensions: [],
+    fecMechanisms: [],
+    rtcp: []
+  };
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
+    var pt = mline[i];
+    var rtpmapline = SDPUtils.matchPrefix(
+        mediaSection, 'a=rtpmap:' + pt + ' ')[0];
+    if (rtpmapline) {
+      var codec = SDPUtils.parseRtpMap(rtpmapline);
+      var fmtps = SDPUtils.matchPrefix(
+          mediaSection, 'a=fmtp:' + pt + ' ');
+      // Only the first a=fmtp:<pt> is considered.
+      codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
+      codec.rtcpFeedback = SDPUtils.matchPrefix(
+          mediaSection, 'a=rtcp-fb:' + pt + ' ')
+        .map(SDPUtils.parseRtcpFb);
+      description.codecs.push(codec);
+      // parse FEC mechanisms from rtpmap lines.
+      switch (codec.name.toUpperCase()) {
+        case 'RED':
+        case 'ULPFEC':
+          description.fecMechanisms.push(codec.name.toUpperCase());
+          break;
+        default: // only RED and ULPFEC are recognized as FEC mechanisms.
+          break;
+      }
+    }
+  }
+  SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
+    description.headerExtensions.push(SDPUtils.parseExtmap(line));
+  });
+  // FIXME: parse rtcp.
+  return description;
+};
+
+// Generates parts of the SDP media section describing the capabilities /
+// parameters.
+SDPUtils.writeRtpDescription = function(kind, caps) {
+  var sdp = '';
+
+  // Build the mline.
+  sdp += 'm=' + kind + ' ';
+  sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
+  sdp += ' UDP/TLS/RTP/SAVPF ';
+  sdp += caps.codecs.map(function(codec) {
+    if (codec.preferredPayloadType !== undefined) {
+      return codec.preferredPayloadType;
+    }
+    return codec.payloadType;
+  }).join(' ') + '\r\n';
+
+  sdp += 'c=IN IP4 0.0.0.0\r\n';
+  sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';
+
+  // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
+  caps.codecs.forEach(function(codec) {
+    sdp += SDPUtils.writeRtpMap(codec);
+    sdp += SDPUtils.writeFmtp(codec);
+    sdp += SDPUtils.writeRtcpFb(codec);
+  });
+  var maxptime = 0;
+  caps.codecs.forEach(function(codec) {
+    if (codec.maxptime > maxptime) {
+      maxptime = codec.maxptime;
+    }
+  });
+  if (maxptime > 0) {
+    sdp += 'a=maxptime:' + maxptime + '\r\n';
+  }
+  sdp += 'a=rtcp-mux\r\n';
+
+  caps.headerExtensions.forEach(function(extension) {
+    sdp += SDPUtils.writeExtmap(extension);
+  });
+  // FIXME: write fecMechanisms.
+  return sdp;
+};
+
+// Parses the SDP media section and returns an array of
+// RTCRtpEncodingParameters.
+SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
+  var encodingParameters = [];
+  var description = SDPUtils.parseRtpParameters(mediaSection);
+  var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
+  var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;
+
+  // filter a=ssrc:... cname:, ignore PlanB-msid
+  var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'cname';
+  });
+  var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
+  var secondarySsrc;
+
+  var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
+  .map(function(line) {
+    var parts = line.split(' ');
+    parts.shift();
+    return parts.map(function(part) {
+      return parseInt(part, 10);
+    });
+  });
+  if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
+    secondarySsrc = flows[0][1];
+  }
+
+  description.codecs.forEach(function(codec) {
+    if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
+      var encParam = {
+        ssrc: primarySsrc,
+        codecPayloadType: parseInt(codec.parameters.apt, 10),
+        rtx: {
+          ssrc: secondarySsrc
+        }
+      };
+      encodingParameters.push(encParam);
+      if (hasRed) {
+        encParam = JSON.parse(JSON.stringify(encParam));
+        encParam.fec = {
+          ssrc: secondarySsrc,
+          mechanism: hasUlpfec ? 'red+ulpfec' : 'red'
+        };
+        encodingParameters.push(encParam);
+      }
+    }
+  });
+  if (encodingParameters.length === 0 && primarySsrc) {
+    encodingParameters.push({
+      ssrc: primarySsrc
+    });
+  }
+
+  // we support both b=AS and b=TIAS but interpret AS as TIAS.
+  var bandwidth = SDPUtils.matchPrefix(mediaSection, 'b=');
+  if (bandwidth.length) {
+    if (bandwidth[0].indexOf('b=TIAS:') === 0) {
+      bandwidth = parseInt(bandwidth[0].substr(7), 10);
+    } else if (bandwidth[0].indexOf('b=AS:') === 0) {
+      // use formula from JSEP to convert b=AS to TIAS value.
+      bandwidth = parseInt(bandwidth[0].substr(5), 10) * 1000 * 0.95
+          - (50 * 40 * 8);
+    } else {
+      bandwidth = undefined;
+    }
+    encodingParameters.forEach(function(params) {
+      params.maxBitrate = bandwidth;
+    });
+  }
+  return encodingParameters;
+};
+
+// parses http://draft.ortc.org/#rtcrtcpparameters*
+SDPUtils.parseRtcpParameters = function(mediaSection) {
+  var rtcpParameters = {};
+
+  var cname;
+  // Gets the first SSRC. Note that with RTX there might be multiple
+  // SSRCs.
+  var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+      .map(function(line) {
+        return SDPUtils.parseSsrcMedia(line);
+      })
+      .filter(function(obj) {
+        return obj.attribute === 'cname';
+      })[0];
+  if (remoteSsrc) {
+    rtcpParameters.cname = remoteSsrc.value;
+    rtcpParameters.ssrc = remoteSsrc.ssrc;
+  }
+
+  // Edge uses the compound attribute instead of reducedSize
+  // compound is !reducedSize
+  var rsize = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-rsize');
+  rtcpParameters.reducedSize = rsize.length > 0;
+  rtcpParameters.compound = rsize.length === 0;
+
+  // parses the rtcp-mux attrіbute.
+  // Note that Edge does not support unmuxed RTCP.
+  var mux = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-mux');
+  rtcpParameters.mux = mux.length > 0;
+
+  return rtcpParameters;
+};
+
+// parses either a=msid: or a=ssrc:... msid lines and returns
+// the id of the MediaStream and MediaStreamTrack.
+SDPUtils.parseMsid = function(mediaSection) {
+  var parts;
+  var spec = SDPUtils.matchPrefix(mediaSection, 'a=msid:');
+  if (spec.length === 1) {
+    parts = spec[0].substr(7).split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+  var planB = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
+  .map(function(line) {
+    return SDPUtils.parseSsrcMedia(line);
+  })
+  .filter(function(parts) {
+    return parts.attribute === 'msid';
+  });
+  if (planB.length > 0) {
+    parts = planB[0].value.split(' ');
+    return {stream: parts[0], track: parts[1]};
+  }
+};
+
+// Generate a session ID for SDP.
+// https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-20#section-5.2.1
+// recommends using a cryptographically random +ve 64-bit value
+// but right now this should be acceptable and within the right range
+SDPUtils.generateSessionId = function() {
+  return Math.random().toString().substr(2, 21);
+};
+
+// Write boilder plate for start of SDP
+// sessId argument is optional - if not supplied it will
+// be generated randomly
+// sessVersion is optional and defaults to 2
+SDPUtils.writeSessionBoilerplate = function(sessId, sessVer) {
+  var sessionId;
+  var version = sessVer !== undefined ? sessVer : 2;
+  if (sessId) {
+    sessionId = sessId;
+  } else {
+    sessionId = SDPUtils.generateSessionId();
+  }
+  // FIXME: sess-id should be an NTP timestamp.
+  return 'v=0\r\n' +
+      'o=thisisadapterortc ' + sessionId + ' ' + version + ' IN IP4 127.0.0.1\r\n' +
+      's=-\r\n' +
+      't=0 0\r\n';
+};
+
+SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
+  var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
+
+  // Map ICE parameters (ufrag, pwd) to SDP.
+  sdp += SDPUtils.writeIceParameters(
+      transceiver.iceGatherer.getLocalParameters());
+
+  // Map DTLS parameters to SDP.
+  sdp += SDPUtils.writeDtlsParameters(
+      transceiver.dtlsTransport.getLocalParameters(),
+      type === 'offer' ? 'actpass' : 'active');
+
+  sdp += 'a=mid:' + transceiver.mid + '\r\n';
+
+  if (transceiver.direction) {
+    sdp += 'a=' + transceiver.direction + '\r\n';
+  } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
+    sdp += 'a=sendrecv\r\n';
+  } else if (transceiver.rtpSender) {
+    sdp += 'a=sendonly\r\n';
+  } else if (transceiver.rtpReceiver) {
+    sdp += 'a=recvonly\r\n';
+  } else {
+    sdp += 'a=inactive\r\n';
+  }
+
+  if (transceiver.rtpSender) {
+    // spec.
+    var msid = 'msid:' + stream.id + ' ' +
+        transceiver.rtpSender.track.id + '\r\n';
+    sdp += 'a=' + msid;
+
+    // for Chrome.
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+        ' ' + msid;
+    if (transceiver.sendEncodingParameters[0].rtx) {
+      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+          ' ' + msid;
+      sdp += 'a=ssrc-group:FID ' +
+          transceiver.sendEncodingParameters[0].ssrc + ' ' +
+          transceiver.sendEncodingParameters[0].rtx.ssrc +
+          '\r\n';
+    }
+  }
+  // FIXME: this should be written by writeRtpDescription.
+  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
+      ' cname:' + SDPUtils.localCName + '\r\n';
+  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
+    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
+        ' cname:' + SDPUtils.localCName + '\r\n';
+  }
+  return sdp;
+};
+
+// Gets the direction from the mediaSection or the sessionpart.
+SDPUtils.getDirection = function(mediaSection, sessionpart) {
+  // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
+  var lines = SDPUtils.splitLines(mediaSection);
+  for (var i = 0; i < lines.length; i++) {
+    switch (lines[i]) {
+      case 'a=sendrecv':
+      case 'a=sendonly':
+      case 'a=recvonly':
+      case 'a=inactive':
+        return lines[i].substr(2);
+      default:
+        // FIXME: What should happen here?
+    }
+  }
+  if (sessionpart) {
+    return SDPUtils.getDirection(sessionpart);
+  }
+  return 'sendrecv';
+};
+
+SDPUtils.getKind = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return mline[0].substr(2);
+};
+
+SDPUtils.isRejected = function(mediaSection) {
+  return mediaSection.split(' ', 2)[1] === '0';
+};
+
+SDPUtils.parseMLine = function(mediaSection) {
+  var lines = SDPUtils.splitLines(mediaSection);
+  var mline = lines[0].split(' ');
+  return {
+    kind: mline[0].substr(2),
+    port: parseInt(mline[1], 10),
+    protocol: mline[2],
+    fmt: mline.slice(3).join(' ')
+  };
+};
+
+// Expose public methods.
+if (typeof module === 'object') {
+  module.exports = SDPUtils;
+}
+
+},{}],3:[function(require,module,exports){
+(function (global){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var adapterFactory = require('./adapter_factory.js');
+module.exports = adapterFactory({window: global.window});
+
+}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
+},{"./adapter_factory.js":4}],4:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+
+'use strict';
+
+var utils = require('./utils');
+// Shimming starts here.
+module.exports = function(dependencies, opts) {
+  var window = dependencies && dependencies.window;
+
+  var options = {
+    shimChrome: true,
+    shimFirefox: true,
+    shimEdge: true,
+    shimSafari: true,
+  };
+
+  for (var key in opts) {
+    if (hasOwnProperty.call(opts, key)) {
+      options[key] = opts[key];
+    }
+  }
+
+  // Utils.
+  var logging = utils.log;
+  var browserDetails = utils.detectBrowser(window);
+
+  // Export to the adapter global object visible in the browser.
+  var adapter = {
+    browserDetails: browserDetails,
+    extractVersion: utils.extractVersion,
+    disableLog: utils.disableLog,
+    disableWarnings: utils.disableWarnings
+  };
+
+  // Uncomment the line below if you want logging to occur, including logging
+  // for the switch statement below. Can also be turned on in the browser via
+  // adapter.disableLog(false), but then logging from the switch statement below
+  // will not appear.
+  // require('./utils').disableLog(false);
+
+  // Browser shims.
+  var chromeShim = require('./chrome/chrome_shim') || null;
+  var edgeShim = require('./edge/edge_shim') || null;
+  var firefoxShim = require('./firefox/firefox_shim') || null;
+  var safariShim = require('./safari/safari_shim') || null;
+  var commonShim = require('./common_shim') || null;
+
+  // Shim browser if found.
+  switch (browserDetails.browser) {
+    case 'chrome':
+      if (!chromeShim || !chromeShim.shimPeerConnection ||
+          !options.shimChrome) {
+        logging('Chrome shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      chromeShim.shimGetUserMedia(window);
+      chromeShim.shimMediaStream(window);
+      chromeShim.shimSourceObject(window);
+      chromeShim.shimPeerConnection(window);
+      chromeShim.shimOnTrack(window);
+      chromeShim.shimAddTrackRemoveTrack(window);
+      chromeShim.shimGetSendersWithDtmf(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'firefox':
+      if (!firefoxShim || !firefoxShim.shimPeerConnection ||
+          !options.shimFirefox) {
+        logging('Firefox shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming firefox.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = firefoxShim;
+      commonShim.shimCreateObjectURL(window);
+
+      firefoxShim.shimGetUserMedia(window);
+      firefoxShim.shimSourceObject(window);
+      firefoxShim.shimPeerConnection(window);
+      firefoxShim.shimOnTrack(window);
+      firefoxShim.shimRemoveStream(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    case 'edge':
+      if (!edgeShim || !edgeShim.shimPeerConnection || !options.shimEdge) {
+        logging('MS edge shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming edge.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = edgeShim;
+      commonShim.shimCreateObjectURL(window);
+
+      edgeShim.shimGetUserMedia(window);
+      edgeShim.shimPeerConnection(window);
+      edgeShim.shimReplaceTrack(window);
+
+      // the edge shim implements the full RTCIceCandidate object.
+      break;
+    case 'safari':
+      if (!safariShim || !options.shimSafari) {
+        logging('Safari shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming safari.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = safariShim;
+      commonShim.shimCreateObjectURL(window);
+
+      safariShim.shimRTCIceServerUrls(window);
+      safariShim.shimCallbacksAPI(window);
+      safariShim.shimLocalStreamsAPI(window);
+      safariShim.shimRemoteStreamsAPI(window);
+      safariShim.shimTrackEventTransceiver(window);
+      safariShim.shimGetUserMedia(window);
+      safariShim.shimCreateOfferLegacy(window);
+
+      commonShim.shimRTCIceCandidate(window);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+
+  return adapter;
+};
+
+},{"./chrome/chrome_shim":5,"./common_shim":7,"./edge/edge_shim":8,"./firefox/firefox_shim":10,"./safari/safari_shim":12,"./utils":13}],5:[function(require,module,exports){
+
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+var chromeShim = {
+  shimMediaStream: function(window) {
+    window.MediaStream = window.MediaStream || window.webkitMediaStream;
+  },
+
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+          }
+          this.addEventListener('track', this._ontrack = f);
+        }
+      });
+      var origSetRemoteDescription =
+          window.RTCPeerConnection.prototype.setRemoteDescription;
+      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
+        var pc = this;
+        if (!pc._ontrackpoly) {
+          pc._ontrackpoly = function(e) {
+            // onaddstream does not fire when a track is added to an existing
+            // stream. But stream.onaddtrack is implemented so we use that.
+            e.stream.addEventListener('addtrack', function(te) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === te.track.id;
+                });
+              } else {
+                receiver = {track: te.track};
+              }
+
+              var event = new Event('track');
+              event.track = te.track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+            e.stream.getTracks().forEach(function(track) {
+              var receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = pc.getReceivers().find(function(r) {
+                  return r.track && r.track.id === track.id;
+                });
+              } else {
+                receiver = {track: track};
+              }
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = receiver;
+              event.transceiver = {receiver: receiver};
+              event.streams = [e.stream];
+              pc.dispatchEvent(event);
+            });
+          };
+          pc.addEventListener('addstream', pc._ontrackpoly);
+        }
+        return origSetRemoteDescription.apply(pc, arguments);
+      };
+    }
+  },
+
+  shimGetSendersWithDtmf: function(window) {
+    // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        !('getSenders' in window.RTCPeerConnection.prototype) &&
+        'createDTMFSender' in window.RTCPeerConnection.prototype) {
+      var shimSenderWithDtmf = function(pc, track) {
+        return {
+          track: track,
+          get dtmf() {
+            if (this._dtmf === undefined) {
+              if (track.kind === 'audio') {
+                this._dtmf = pc.createDTMFSender(track);
+              } else {
+                this._dtmf = null;
+              }
+            }
+            return this._dtmf;
+          },
+          _pc: pc
+        };
+      };
+
+      // augment addTrack when getSenders is not available.
+      if (!window.RTCPeerConnection.prototype.getSenders) {
+        window.RTCPeerConnection.prototype.getSenders = function() {
+          this._senders = this._senders || [];
+          return this._senders.slice(); // return a copy of the internal state.
+        };
+        var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+        window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+          var pc = this;
+          var sender = origAddTrack.apply(pc, arguments);
+          if (!sender) {
+            sender = shimSenderWithDtmf(pc, track);
+            pc._senders.push(sender);
+          }
+          return sender;
+        };
+
+        var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+        window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+          var pc = this;
+          origRemoveTrack.apply(pc, arguments);
+          var idx = pc._senders.indexOf(sender);
+          if (idx !== -1) {
+            pc._senders.splice(idx, 1);
+          }
+        };
+      }
+      var origAddStream = window.RTCPeerConnection.prototype.addStream;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origAddStream.apply(pc, [stream]);
+        stream.getTracks().forEach(function(track) {
+          pc._senders.push(shimSenderWithDtmf(pc, track));
+        });
+      };
+
+      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        var pc = this;
+        pc._senders = pc._senders || [];
+        origRemoveStream.apply(pc, [stream]);
+
+        stream.getTracks().forEach(function(track) {
+          var sender = pc._senders.find(function(s) {
+            return s.track === track;
+          });
+          if (sender) {
+            pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
+          }
+        });
+      };
+    } else if (typeof window === 'object' && window.RTCPeerConnection &&
+               'getSenders' in window.RTCPeerConnection.prototype &&
+               'createDTMFSender' in window.RTCPeerConnection.prototype &&
+               window.RTCRtpSender &&
+               !('dtmf' in window.RTCRtpSender.prototype)) {
+      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+      window.RTCPeerConnection.prototype.getSenders = function() {
+        var pc = this;
+        var senders = origGetSenders.apply(pc, []);
+        senders.forEach(function(sender) {
+          sender._pc = pc;
+        });
+        return senders;
+      };
+
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = this._pc.createDTMFSender(this.track);
+            } else {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    var URL = window && window.URL;
+
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this._srcObject;
+          },
+          set: function(stream) {
+            var self = this;
+            // Use _srcObject as a private property for this shim
+            this._srcObject = stream;
+            if (this.src) {
+              URL.revokeObjectURL(this.src);
+            }
+
+            if (!stream) {
+              this.src = '';
+              return undefined;
+            }
+            this.src = URL.createObjectURL(stream);
+            // We need to recreate the blob url when a track is added or
+            // removed. Doing it manually since we want to avoid a recursion.
+            stream.addEventListener('addtrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+            stream.addEventListener('removetrack', function() {
+              if (self.src) {
+                URL.revokeObjectURL(self.src);
+              }
+              self.src = URL.createObjectURL(stream);
+            });
+          }
+        });
+      }
+    }
+  },
+
+  shimAddTrackRemoveTrack: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+    // shim addTrack and removeTrack.
+    if (window.RTCPeerConnection.prototype.addTrack &&
+        browserDetails.version >= 64) {
+      return;
+    }
+
+    // also shim pc.getLocalStreams when addTrack is shimmed
+    // to return the original streams.
+    var origGetLocalStreams = window.RTCPeerConnection.prototype
+        .getLocalStreams;
+    window.RTCPeerConnection.prototype.getLocalStreams = function() {
+      var self = this;
+      var nativeStreams = origGetLocalStreams.apply(this);
+      self._reverseStreams = self._reverseStreams || {};
+      return nativeStreams.map(function(stream) {
+        return self._reverseStreams[stream.id];
+      });
+    };
+
+    var origAddStream = window.RTCPeerConnection.prototype.addStream;
+    window.RTCPeerConnection.prototype.addStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      stream.getTracks().forEach(function(track) {
+        var alreadyExists = pc.getSenders().find(function(s) {
+          return s.track === track;
+        });
+        if (alreadyExists) {
+          throw new DOMException('Track already exists.',
+              'InvalidAccessError');
+        }
+      });
+      // Add identity mapping for consistency with addTrack.
+      // Unless this is being used with a stream from addTrack.
+      if (!pc._reverseStreams[stream.id]) {
+        var newStream = new window.MediaStream(stream.getTracks());
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        stream = newStream;
+      }
+      origAddStream.apply(pc, [stream]);
+    };
+
+    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+
+      origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
+      delete pc._reverseStreams[(pc._streams[stream.id] ?
+          pc._streams[stream.id].id : stream.id)];
+      delete pc._streams[stream.id];
+    };
+
+    window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      var streams = [].slice.call(arguments, 1);
+      if (streams.length !== 1 ||
+          !streams[0].getTracks().find(function(t) {
+            return t === track;
+          })) {
+        // this is not fully correct but all we can manage without
+        // [[associated MediaStreams]] internal slot.
+        throw new DOMException(
+          'The adapter.js addTrack polyfill only supports a single ' +
+          ' stream which is associated with the specified track.',
+          'NotSupportedError');
+      }
+
+      var alreadyExists = pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+            'InvalidAccessError');
+      }
+
+      pc._streams = pc._streams || {};
+      pc._reverseStreams = pc._reverseStreams || {};
+      var oldStream = pc._streams[stream.id];
+      if (oldStream) {
+        // this is using odd Chrome behaviour, use with caution:
+        // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
+        // Note: we rely on the high-level addTrack/dtmf shim to
+        // create the sender with a dtmf sender.
+        oldStream.addTrack(track);
+
+        // Trigger ONN async.
+        Promise.resolve().then(function() {
+          pc.dispatchEvent(new Event('negotiationneeded'));
+        });
+      } else {
+        var newStream = new window.MediaStream([track]);
+        pc._streams[stream.id] = newStream;
+        pc._reverseStreams[newStream.id] = stream;
+        pc.addStream(newStream);
+      }
+      return pc.getSenders().find(function(s) {
+        return s.track === track;
+      });
+    };
+
+    // replace the internal stream id with the external one and
+    // vice versa.
+    function replaceInternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
+            externalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    function replaceExternalStreamId(pc, description) {
+      var sdp = description.sdp;
+      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
+        var externalStream = pc._reverseStreams[internalId];
+        var internalStream = pc._streams[externalStream.id];
+        sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
+            internalStream.id);
+      });
+      return new RTCSessionDescription({
+        type: description.type,
+        sdp: sdp
+      });
+    }
+    ['createOffer', 'createAnswer'].forEach(function(method) {
+      var nativeMethod = window.RTCPeerConnection.prototype[method];
+      window.RTCPeerConnection.prototype[method] = function() {
+        var pc = this;
+        var args = arguments;
+        var isLegacyCall = arguments.length &&
+            typeof arguments[0] === 'function';
+        if (isLegacyCall) {
+          return nativeMethod.apply(pc, [
+            function(description) {
+              var desc = replaceInternalStreamId(pc, description);
+              args[0].apply(null, [desc]);
+            },
+            function(err) {
+              if (args[1]) {
+                args[1].apply(null, err);
+              }
+            }, arguments[2]
+          ]);
+        }
+        return nativeMethod.apply(pc, arguments)
+        .then(function(description) {
+          return replaceInternalStreamId(pc, description);
+        });
+      };
+    });
+
+    var origSetLocalDescription =
+        window.RTCPeerConnection.prototype.setLocalDescription;
+    window.RTCPeerConnection.prototype.setLocalDescription = function() {
+      var pc = this;
+      if (!arguments.length || !arguments[0].type) {
+        return origSetLocalDescription.apply(pc, arguments);
+      }
+      arguments[0] = replaceExternalStreamId(pc, arguments[0]);
+      return origSetLocalDescription.apply(pc, arguments);
+    };
+
+    // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
+
+    var origLocalDescription = Object.getOwnPropertyDescriptor(
+        window.RTCPeerConnection.prototype, 'localDescription');
+    Object.defineProperty(window.RTCPeerConnection.prototype,
+        'localDescription', {
+          get: function() {
+            var pc = this;
+            var description = origLocalDescription.get.apply(this);
+            if (description.type === '') {
+              return description;
+            }
+            return replaceInternalStreamId(pc, description);
+          }
+        });
+
+    window.RTCPeerConnection.prototype.removeTrack = function(sender) {
+      var pc = this;
+      if (pc.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      // We can not yet check for sender instanceof RTCRtpSender
+      // since we shim RTPSender. So we check if sender._pc is set.
+      if (!sender._pc) {
+        throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
+            'does not implement interface RTCRtpSender.', 'TypeError');
+      }
+      var isLocal = sender._pc === pc;
+      if (!isLocal) {
+        throw new DOMException('Sender was not created by this connection.',
+            'InvalidAccessError');
+      }
+
+      // Search for the native stream the senders track belongs to.
+      pc._streams = pc._streams || {};
+      var stream;
+      Object.keys(pc._streams).forEach(function(streamid) {
+        var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
+          return sender.track === track;
+        });
+        if (hasTrack) {
+          stream = pc._streams[streamid];
+        }
+      });
+
+      if (stream) {
+        if (stream.getTracks().length === 1) {
+          // if this is the last track of the stream, remove the stream. This
+          // takes care of any shimmed _senders.
+          pc.removeStream(pc._reverseStreams[stream.id]);
+        } else {
+          // relying on the same odd chrome behaviour as above.
+          stream.removeTrack(sender.track);
+        }
+        pc.dispatchEvent(new Event('negotiationneeded'));
+      }
+    };
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        // Translate iceTransportPolicy to iceTransports,
+        // see https://code.google.com/p/webrtc/issues/detail?id=4869
+        // this was fixed in M56 along with unprefixing RTCPeerConnection.
+        logging('PeerConnection');
+        if (pcConfig && pcConfig.iceTransportPolicy) {
+          pcConfig.iceTransports = pcConfig.iceTransportPolicy;
+        }
+
+        return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.webkitRTCPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      if (window.webkitRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.webkitRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+    } else {
+      // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+      var OrigPeerConnection = window.RTCPeerConnection;
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (pcConfig && pcConfig.iceServers) {
+          var newIceServers = [];
+          for (var i = 0; i < pcConfig.iceServers.length; i++) {
+            var server = pcConfig.iceServers[i];
+            if (!server.hasOwnProperty('urls') &&
+                server.hasOwnProperty('url')) {
+              utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+              server = JSON.parse(JSON.stringify(server));
+              server.urls = server.url;
+              newIceServers.push(server);
+            } else {
+              newIceServers.push(pcConfig.iceServers[i]);
+            }
+          }
+          pcConfig.iceServers = newIceServers;
+        }
+        return new OrigPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+      // wrap static methods. Currently just generateCertificate.
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+
+    var origGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(selector,
+        successCallback, errorCallback) {
+      var self = this;
+      var args = arguments;
+
+      // If selector is a function then we are in the old style stats so just
+      // pass back the original getStats format to avoid breaking old users.
+      if (arguments.length > 0 && typeof selector === 'function') {
+        return origGetStats.apply(this, arguments);
+      }
+
+      // When spec-style getStats is supported, return those when called with
+      // either no arguments or the selector argument is null.
+      if (origGetStats.length === 0 && (arguments.length === 0 ||
+          typeof arguments[0] !== 'function')) {
+        return origGetStats.apply(this, []);
+      }
+
+      var fixChromeStats_ = function(response) {
+        var standardReport = {};
+        var reports = response.result();
+        reports.forEach(function(report) {
+          var standardStats = {
+            id: report.id,
+            timestamp: report.timestamp,
+            type: {
+              localcandidate: 'local-candidate',
+              remotecandidate: 'remote-candidate'
+            }[report.type] || report.type
+          };
+          report.names().forEach(function(name) {
+            standardStats[name] = report.stat(name);
+          });
+          standardReport[standardStats.id] = standardStats;
+        });
+
+        return standardReport;
+      };
+
+      // shim getStats with maplike support
+      var makeMapStats = function(stats) {
+        return new Map(Object.keys(stats).map(function(key) {
+          return [key, stats[key]];
+        }));
+      };
+
+      if (arguments.length >= 2) {
+        var successCallbackWrapper_ = function(response) {
+          args[1](makeMapStats(fixChromeStats_(response)));
+        };
+
+        return origGetStats.apply(this, [successCallbackWrapper_,
+          arguments[0]]);
+      }
+
+      // promise-support
+      return new Promise(function(resolve, reject) {
+        origGetStats.apply(self, [
+          function(response) {
+            resolve(makeMapStats(fixChromeStats_(response)));
+          }, reject]);
+      }).then(successCallback, errorCallback);
+    };
+
+    // add promise support -- natively available in Chrome 51
+    if (browserDetails.version < 51) {
+      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+          .forEach(function(method) {
+            var nativeMethod = window.RTCPeerConnection.prototype[method];
+            window.RTCPeerConnection.prototype[method] = function() {
+              var args = arguments;
+              var self = this;
+              var promise = new Promise(function(resolve, reject) {
+                nativeMethod.apply(self, [args[0], resolve, reject]);
+              });
+              if (args.length < 2) {
+                return promise;
+              }
+              return promise.then(function() {
+                args[1].apply(null, []);
+              },
+              function(err) {
+                if (args.length >= 3) {
+                  args[2].apply(null, [err]);
+                }
+              });
+            };
+          });
+    }
+
+    // promise support for createOffer and createAnswer. Available (without
+    // bugs) since M52: crbug/619289
+    if (browserDetails.version < 52) {
+      ['createOffer', 'createAnswer'].forEach(function(method) {
+        var nativeMethod = window.RTCPeerConnection.prototype[method];
+        window.RTCPeerConnection.prototype[method] = function() {
+          var self = this;
+          if (arguments.length < 1 || (arguments.length === 1 &&
+              typeof arguments[0] === 'object')) {
+            var opts = arguments.length === 1 ? arguments[0] : undefined;
+            return new Promise(function(resolve, reject) {
+              nativeMethod.apply(self, [resolve, reject, opts]);
+            });
+          }
+          return nativeMethod.apply(this, arguments);
+        };
+      });
+    }
+
+    // shim implicit creation of RTCSessionDescription/RTCIceCandidate
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+  }
+};
+
+
+// Expose public methods.
+module.exports = {
+  shimMediaStream: chromeShim.shimMediaStream,
+  shimOnTrack: chromeShim.shimOnTrack,
+  shimAddTrackRemoveTrack: chromeShim.shimAddTrackRemoveTrack,
+  shimGetSendersWithDtmf: chromeShim.shimGetSendersWithDtmf,
+  shimSourceObject: chromeShim.shimSourceObject,
+  shimPeerConnection: chromeShim.shimPeerConnection,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils.js":13,"./getusermedia":6}],6:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+var utils = require('../utils.js');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+
+  var constraintsToChrome_ = function(c) {
+    if (typeof c !== 'object' || c.mandatory || c.optional) {
+      return c;
+    }
+    var cc = {};
+    Object.keys(c).forEach(function(key) {
+      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+        return;
+      }
+      var r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
+      if (r.exact !== undefined && typeof r.exact === 'number') {
+        r.min = r.max = r.exact;
+      }
+      var oldname_ = function(prefix, name) {
+        if (prefix) {
+          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+        }
+        return (name === 'deviceId') ? 'sourceId' : name;
+      };
+      if (r.ideal !== undefined) {
+        cc.optional = cc.optional || [];
+        var oc = {};
+        if (typeof r.ideal === 'number') {
+          oc[oldname_('min', key)] = r.ideal;
+          cc.optional.push(oc);
+          oc = {};
+          oc[oldname_('max', key)] = r.ideal;
+          cc.optional.push(oc);
+        } else {
+          oc[oldname_('', key)] = r.ideal;
+          cc.optional.push(oc);
+        }
+      }
+      if (r.exact !== undefined && typeof r.exact !== 'number') {
+        cc.mandatory = cc.mandatory || {};
+        cc.mandatory[oldname_('', key)] = r.exact;
+      } else {
+        ['min', 'max'].forEach(function(mix) {
+          if (r[mix] !== undefined) {
+            cc.mandatory = cc.mandatory || {};
+            cc.mandatory[oldname_(mix, key)] = r[mix];
+          }
+        });
+      }
+    });
+    if (c.advanced) {
+      cc.optional = (cc.optional || []).concat(c.advanced);
+    }
+    return cc;
+  };
+
+  var shimConstraints_ = function(constraints, func) {
+    if (browserDetails.version >= 61) {
+      return func(constraints);
+    }
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (constraints && typeof constraints.audio === 'object') {
+      var remap = function(obj, a, b) {
+        if (a in obj && !(b in obj)) {
+          obj[b] = obj[a];
+          delete obj[a];
+        }
+      };
+      constraints = JSON.parse(JSON.stringify(constraints));
+      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
+      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
+      constraints.audio = constraintsToChrome_(constraints.audio);
+    }
+    if (constraints && typeof constraints.video === 'object') {
+      // Shim facingMode for mobile & surface pro.
+      var face = constraints.video.facingMode;
+      face = face && ((typeof face === 'object') ? face : {ideal: face});
+      var getSupportedFacingModeLies = browserDetails.version < 66;
+
+      if ((face && (face.exact === 'user' || face.exact === 'environment' ||
+                    face.ideal === 'user' || face.ideal === 'environment')) &&
+          !(navigator.mediaDevices.getSupportedConstraints &&
+            navigator.mediaDevices.getSupportedConstraints().facingMode &&
+            !getSupportedFacingModeLies)) {
+        delete constraints.video.facingMode;
+        var matches;
+        if (face.exact === 'environment' || face.ideal === 'environment') {
+          matches = ['back', 'rear'];
+        } else if (face.exact === 'user' || face.ideal === 'user') {
+          matches = ['front'];
+        }
+        if (matches) {
+          // Look for matches in label, or use last cam for back (typical).
+          return navigator.mediaDevices.enumerateDevices()
+          .then(function(devices) {
+            devices = devices.filter(function(d) {
+              return d.kind === 'videoinput';
+            });
+            var dev = devices.find(function(d) {
+              return matches.some(function(match) {
+                return d.label.toLowerCase().indexOf(match) !== -1;
+              });
+            });
+            if (!dev && devices.length && matches.indexOf('back') !== -1) {
+              dev = devices[devices.length - 1]; // more likely the back cam
+            }
+            if (dev) {
+              constraints.video.deviceId = face.exact ? {exact: dev.deviceId} :
+                                                        {ideal: dev.deviceId};
+            }
+            constraints.video = constraintsToChrome_(constraints.video);
+            logging('chrome: ' + JSON.stringify(constraints));
+            return func(constraints);
+          });
+        }
+      }
+      constraints.video = constraintsToChrome_(constraints.video);
+    }
+    logging('chrome: ' + JSON.stringify(constraints));
+    return func(constraints);
+  };
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        PermissionDeniedError: 'NotAllowedError',
+        InvalidStateError: 'NotReadableError',
+        DevicesNotFoundError: 'NotFoundError',
+        ConstraintNotSatisfiedError: 'OverconstrainedError',
+        TrackStartError: 'NotReadableError',
+        MediaDeviceFailedDueToShutdown: 'NotReadableError',
+        MediaDeviceKillSwitchOn: 'NotReadableError'
+      }[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraintName,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    shimConstraints_(constraints, function(c) {
+      navigator.webkitGetUserMedia(c, onSuccess, function(e) {
+        if (onError) {
+          onError(shimError_(e));
+        }
+      });
+    });
+  };
+
+  navigator.getUserMedia = getUserMedia_;
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      navigator.getUserMedia(constraints, resolve, reject);
+    });
+  };
+
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {
+      getUserMedia: getUserMediaPromise_,
+      enumerateDevices: function() {
+        return new Promise(function(resolve) {
+          var kinds = {audio: 'audioinput', video: 'videoinput'};
+          return window.MediaStreamTrack.getSources(function(devices) {
+            resolve(devices.map(function(device) {
+              return {label: device.label,
+                kind: kinds[device.kind],
+                deviceId: device.id,
+                groupId: ''};
+            }));
+          });
+        });
+      },
+      getSupportedConstraints: function() {
+        return {
+          deviceId: true, echoCancellation: true, facingMode: true,
+          frameRate: true, height: true, width: true
+        };
+      }
+    };
+  }
+
+  // A shim for getUserMedia method on the mediaDevices object.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (!navigator.mediaDevices.getUserMedia) {
+    navigator.mediaDevices.getUserMedia = function(constraints) {
+      return getUserMediaPromise_(constraints);
+    };
+  } else {
+    // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
+    // function which returns a Promise, it does not accept spec-style
+    // constraints.
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(cs) {
+      return shimConstraints_(cs, function(c) {
+        return origGetUserMedia(c).then(function(stream) {
+          if (c.audio && !stream.getAudioTracks().length ||
+              c.video && !stream.getVideoTracks().length) {
+            stream.getTracks().forEach(function(track) {
+              track.stop();
+            });
+            throw new DOMException('', 'NotFoundError');
+          }
+          return stream;
+        }, function(e) {
+          return Promise.reject(shimError_(e));
+        });
+      });
+    };
+  }
+
+  // Dummy devicechange event methods.
+  // TODO(KaptenJansson) remove once implemented in Chrome stable.
+  if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
+    navigator.mediaDevices.addEventListener = function() {
+      logging('Dummy mediaDevices.addEventListener called.');
+    };
+  }
+  if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
+    navigator.mediaDevices.removeEventListener = function() {
+      logging('Dummy mediaDevices.removeEventListener called.');
+    };
+  }
+};
+
+},{"../utils.js":13}],7:[function(require,module,exports){
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var SDPUtils = require('sdp');
+var utils = require('./utils');
+
+// Wraps the peerconnection event eventNameToWrap in a function
+// which returns the modified event object.
+function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  var proto = window.RTCPeerConnection.prototype;
+  var nativeAddEventListener = proto.addEventListener;
+  proto.addEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap) {
+      return nativeAddEventListener.apply(this, arguments);
+    }
+    var wrappedCallback = function(e) {
+      cb(wrapper(e));
+    };
+    this._eventMap = this._eventMap || {};
+    this._eventMap[cb] = wrappedCallback;
+    return nativeAddEventListener.apply(this, [nativeEventName,
+      wrappedCallback]);
+  };
+
+  var nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap
+        || !this._eventMap[cb]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    var unwrappedCb = this._eventMap[cb];
+    delete this._eventMap[cb];
+    return nativeRemoveEventListener.apply(this, [nativeEventName,
+      unwrappedCb]);
+  };
+
+  Object.defineProperty(proto, 'on' + eventNameToWrap, {
+    get: function() {
+      return this['_on' + eventNameToWrap];
+    },
+    set: function(cb) {
+      if (this['_on' + eventNameToWrap]) {
+        this.removeEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap]);
+        delete this['_on' + eventNameToWrap];
+      }
+      if (cb) {
+        this.addEventListener(eventNameToWrap,
+            this['_on' + eventNameToWrap] = cb);
+      }
+    }
+  });
+}
+
+module.exports = {
+  shimRTCIceCandidate: function(window) {
+    // foundation is arbitrarily chosen as an indicator for full support for
+    // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
+    if (window.RTCIceCandidate && 'foundation' in
+        window.RTCIceCandidate.prototype) {
+      return;
+    }
+
+    var NativeRTCIceCandidate = window.RTCIceCandidate;
+    window.RTCIceCandidate = function(args) {
+      // Remove the a= which shouldn't be part of the candidate string.
+      if (typeof args === 'object' && args.candidate &&
+          args.candidate.indexOf('a=') === 0) {
+        args = JSON.parse(JSON.stringify(args));
+        args.candidate = args.candidate.substr(2);
+      }
+
+      // Augment the native candidate with the parsed fields.
+      var nativeCandidate = new NativeRTCIceCandidate(args);
+      var parsedCandidate = SDPUtils.parseCandidate(args.candidate);
+      var augmentedCandidate = Object.assign(nativeCandidate,
+          parsedCandidate);
+
+      // Add a serializer that does not serialize the extra attributes.
+      augmentedCandidate.toJSON = function() {
+        return {
+          candidate: augmentedCandidate.candidate,
+          sdpMid: augmentedCandidate.sdpMid,
+          sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
+          usernameFragment: augmentedCandidate.usernameFragment,
+        };
+      };
+      return augmentedCandidate;
+    };
+
+    // Hook up the augmented candidate in onicecandidate and
+    // addEventListener('icecandidate', ...)
+    wrapPeerConnectionEvent(window, 'icecandidate', function(e) {
+      if (e.candidate) {
+        Object.defineProperty(e, 'candidate', {
+          value: new window.RTCIceCandidate(e.candidate),
+          writable: 'false'
+        });
+      }
+      return e;
+    });
+  },
+
+  // shimCreateObjectURL must be called before shimSourceObject to avoid loop.
+
+  shimCreateObjectURL: function(window) {
+    var URL = window && window.URL;
+
+    if (!(typeof window === 'object' && window.HTMLMediaElement &&
+          'srcObject' in window.HTMLMediaElement.prototype &&
+        URL.createObjectURL && URL.revokeObjectURL)) {
+      // Only shim CreateObjectURL using srcObject if srcObject exists.
+      return undefined;
+    }
+
+    var nativeCreateObjectURL = URL.createObjectURL.bind(URL);
+    var nativeRevokeObjectURL = URL.revokeObjectURL.bind(URL);
+    var streams = new Map(), newId = 0;
+
+    URL.createObjectURL = function(stream) {
+      if ('getTracks' in stream) {
+        var url = 'polyblob:' + (++newId);
+        streams.set(url, stream);
+        utils.deprecated('URL.createObjectURL(stream)',
+            'elem.srcObject = stream');
+        return url;
+      }
+      return nativeCreateObjectURL(stream);
+    };
+    URL.revokeObjectURL = function(url) {
+      nativeRevokeObjectURL(url);
+      streams.delete(url);
+    };
+
+    var dsc = Object.getOwnPropertyDescriptor(window.HTMLMediaElement.prototype,
+                                              'src');
+    Object.defineProperty(window.HTMLMediaElement.prototype, 'src', {
+      get: function() {
+        return dsc.get.apply(this);
+      },
+      set: function(url) {
+        this.srcObject = streams.get(url) || null;
+        return dsc.set.apply(this, [url]);
+      }
+    });
+
+    var nativeSetAttribute = window.HTMLMediaElement.prototype.setAttribute;
+    window.HTMLMediaElement.prototype.setAttribute = function() {
+      if (arguments.length === 2 &&
+          ('' + arguments[0]).toLowerCase() === 'src') {
+        this.srcObject = streams.get(arguments[1]) || null;
+      }
+      return nativeSetAttribute.apply(this, arguments);
+    };
+  }
+};
+
+},{"./utils":13,"sdp":2}],8:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var shimRTCPeerConnection = require('rtcpeerconnection-shim');
+
+module.exports = {
+  shimGetUserMedia: require('./getusermedia'),
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (window.RTCIceGatherer) {
+      // ORTC defines an RTCIceCandidate object but no constructor.
+      // Not implemented in Edge.
+      if (!window.RTCIceCandidate) {
+        window.RTCIceCandidate = function(args) {
+          return args;
+        };
+      }
+      // ORTC does not have a session description object but
+      // other browsers (i.e. Chrome) that will support both PC and ORTC
+      // in the future might have this defined already.
+      if (!window.RTCSessionDescription) {
+        window.RTCSessionDescription = function(args) {
+          return args;
+        };
+      }
+      // this adds an additional event listener to MediaStrackTrack that signals
+      // when a tracks enabled property was changed. Workaround for a bug in
+      // addStream, see below. No longer required in 15025+
+      if (browserDetails.version < 15025) {
+        var origMSTEnabled = Object.getOwnPropertyDescriptor(
+            window.MediaStreamTrack.prototype, 'enabled');
+        Object.defineProperty(window.MediaStreamTrack.prototype, 'enabled', {
+          set: function(value) {
+            origMSTEnabled.set.call(this, value);
+            var ev = new Event('enabled');
+            ev.enabled = value;
+            this.dispatchEvent(ev);
+          }
+        });
+      }
+    }
+
+    // ORTC defines the DTMF sender a bit different.
+    // https://github.com/w3c/ortc/issues/714
+    if (window.RTCRtpSender && !('dtmf' in window.RTCRtpSender.prototype)) {
+      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+        get: function() {
+          if (this._dtmf === undefined) {
+            if (this.track.kind === 'audio') {
+              this._dtmf = new window.RTCDtmfSender(this);
+            } else if (this.track.kind === 'video') {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        }
+      });
+    }
+
+    window.RTCPeerConnection =
+        shimRTCPeerConnection(window, browserDetails.version);
+  },
+  shimReplaceTrack: function(window) {
+    // ORTC has replaceTrack -- https://github.com/w3c/ortc/issues/614
+    if (window.RTCRtpSender &&
+        !('replaceTrack' in window.RTCRtpSender.prototype)) {
+      window.RTCRtpSender.prototype.replaceTrack =
+          window.RTCRtpSender.prototype.setTrack;
+    }
+  }
+};
+
+},{"../utils":13,"./getusermedia":9,"rtcpeerconnection-shim":1}],9:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+// Expose public methods.
+module.exports = function(window) {
+  var navigator = window && window.navigator;
+
+  var shimError_ = function(e) {
+    return {
+      name: {PermissionDeniedError: 'NotAllowedError'}[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name;
+      }
+    };
+  };
+
+  // getUserMedia error shim.
+  var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+      bind(navigator.mediaDevices);
+  navigator.mediaDevices.getUserMedia = function(c) {
+    return origGetUserMedia(c).catch(function(e) {
+      return Promise.reject(shimError_(e));
+    });
+  };
+};
+
+},{}],10:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+
+var firefoxShim = {
+  shimOnTrack: function(window) {
+    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+        window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+        get: function() {
+          return this._ontrack;
+        },
+        set: function(f) {
+          if (this._ontrack) {
+            this.removeEventListener('track', this._ontrack);
+            this.removeEventListener('addstream', this._ontrackpoly);
+          }
+          this.addEventListener('track', this._ontrack = f);
+          this.addEventListener('addstream', this._ontrackpoly = function(e) {
+            e.stream.getTracks().forEach(function(track) {
+              var event = new Event('track');
+              event.track = track;
+              event.receiver = {track: track};
+              event.transceiver = {receiver: event.receiver};
+              event.streams = [e.stream];
+              this.dispatchEvent(event);
+            }.bind(this));
+          }.bind(this));
+        }
+      });
+    }
+    if (typeof window === 'object' && window.RTCTrackEvent &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        !('transceiver' in window.RTCTrackEvent.prototype)) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimSourceObject: function(window) {
+    // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
+    if (typeof window === 'object') {
+      if (window.HTMLMediaElement &&
+        !('srcObject' in window.HTMLMediaElement.prototype)) {
+        // Shim the srcObject property, once, when HTMLMediaElement is found.
+        Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
+          get: function() {
+            return this.mozSrcObject;
+          },
+          set: function(stream) {
+            this.mozSrcObject = stream;
+          }
+        });
+      }
+    }
+  },
+
+  shimPeerConnection: function(window) {
+    var browserDetails = utils.detectBrowser(window);
+
+    if (typeof window !== 'object' || !(window.RTCPeerConnection ||
+        window.mozRTCPeerConnection)) {
+      return; // probably media.peerconnection.enabled=false in about:config
+    }
+    // The RTCPeerConnection object.
+    if (!window.RTCPeerConnection) {
+      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+        if (browserDetails.version < 38) {
+          // .urls is not supported in FF < 38.
+          // create RTCIceServers with a single url.
+          if (pcConfig && pcConfig.iceServers) {
+            var newIceServers = [];
+            for (var i = 0; i < pcConfig.iceServers.length; i++) {
+              var server = pcConfig.iceServers[i];
+              if (server.hasOwnProperty('urls')) {
+                for (var j = 0; j < server.urls.length; j++) {
+                  var newServer = {
+                    url: server.urls[j]
+                  };
+                  if (server.urls[j].indexOf('turn') === 0) {
+                    newServer.username = server.username;
+                    newServer.credential = server.credential;
+                  }
+                  newIceServers.push(newServer);
+                }
+              } else {
+                newIceServers.push(pcConfig.iceServers[i]);
+              }
+            }
+            pcConfig.iceServers = newIceServers;
+          }
+        }
+        return new window.mozRTCPeerConnection(pcConfig, pcConstraints);
+      };
+      window.RTCPeerConnection.prototype =
+          window.mozRTCPeerConnection.prototype;
+
+      // wrap static methods. Currently just generateCertificate.
+      if (window.mozRTCPeerConnection.generateCertificate) {
+        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+          get: function() {
+            return window.mozRTCPeerConnection.generateCertificate;
+          }
+        });
+      }
+
+      window.RTCSessionDescription = window.mozRTCSessionDescription;
+      window.RTCIceCandidate = window.mozRTCIceCandidate;
+    }
+
+    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+        .forEach(function(method) {
+          var nativeMethod = window.RTCPeerConnection.prototype[method];
+          window.RTCPeerConnection.prototype[method] = function() {
+            arguments[0] = new ((method === 'addIceCandidate') ?
+                window.RTCIceCandidate :
+                window.RTCSessionDescription)(arguments[0]);
+            return nativeMethod.apply(this, arguments);
+          };
+        });
+
+    // support for addIceCandidate(null or undefined)
+    var nativeAddIceCandidate =
+        window.RTCPeerConnection.prototype.addIceCandidate;
+    window.RTCPeerConnection.prototype.addIceCandidate = function() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+
+    // shim getStats with maplike support
+    var makeMapStats = function(stats) {
+      var map = new Map();
+      Object.keys(stats).forEach(function(key) {
+        map.set(key, stats[key]);
+        map[key] = stats[key];
+      });
+      return map;
+    };
+
+    var modernStatsTypes = {
+      inboundrtp: 'inbound-rtp',
+      outboundrtp: 'outbound-rtp',
+      candidatepair: 'candidate-pair',
+      localcandidate: 'local-candidate',
+      remotecandidate: 'remote-candidate'
+    };
+
+    var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
+    window.RTCPeerConnection.prototype.getStats = function(
+      selector,
+      onSucc,
+      onErr
+    ) {
+      return nativeGetStats.apply(this, [selector || null])
+        .then(function(stats) {
+          if (browserDetails.version < 48) {
+            stats = makeMapStats(stats);
+          }
+          if (browserDetails.version < 53 && !onSucc) {
+            // Shim only promise getStats with spec-hyphens in type names
+            // Leave callback version alone; misc old uses of forEach before Map
+            try {
+              stats.forEach(function(stat) {
+                stat.type = modernStatsTypes[stat.type] || stat.type;
+              });
+            } catch (e) {
+              if (e.name !== 'TypeError') {
+                throw e;
+              }
+              // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
+              stats.forEach(function(stat, i) {
+                stats.set(i, Object.assign({}, stat, {
+                  type: modernStatsTypes[stat.type] || stat.type
+                }));
+              });
+            }
+          }
+          return stats;
+        })
+        .then(onSucc, onErr);
+    };
+  },
+
+  shimRemoveStream: function(window) {
+    if (!window.RTCPeerConnection ||
+        'removeStream' in window.RTCPeerConnection.prototype) {
+      return;
+    }
+    window.RTCPeerConnection.prototype.removeStream = function(stream) {
+      var pc = this;
+      utils.deprecated('removeStream', 'removeTrack');
+      this.getSenders().forEach(function(sender) {
+        if (sender.track && stream.getTracks().indexOf(sender.track) !== -1) {
+          pc.removeTrack(sender);
+        }
+      });
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimOnTrack: firefoxShim.shimOnTrack,
+  shimSourceObject: firefoxShim.shimSourceObject,
+  shimPeerConnection: firefoxShim.shimPeerConnection,
+  shimRemoveStream: firefoxShim.shimRemoveStream,
+  shimGetUserMedia: require('./getusermedia')
+};
+
+},{"../utils":13,"./getusermedia":11}],11:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var utils = require('../utils');
+var logging = utils.log;
+
+// Expose public methods.
+module.exports = function(window) {
+  var browserDetails = utils.detectBrowser(window);
+  var navigator = window && window.navigator;
+  var MediaStreamTrack = window && window.MediaStreamTrack;
+
+  var shimError_ = function(e) {
+    return {
+      name: {
+        InternalError: 'NotReadableError',
+        NotSupportedError: 'TypeError',
+        PermissionDeniedError: 'NotAllowedError',
+        SecurityError: 'NotAllowedError'
+      }[e.name] || e.name,
+      message: {
+        'The operation is insecure.': 'The request is not allowed by the ' +
+        'user agent or the platform in the current context.'
+      }[e.message] || e.message,
+      constraint: e.constraint,
+      toString: function() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  // getUserMedia constraints shim.
+  var getUserMedia_ = function(constraints, onSuccess, onError) {
+    var constraintsToFF37_ = function(c) {
+      if (typeof c !== 'object' || c.require) {
+        return c;
+      }
+      var require = [];
+      Object.keys(c).forEach(function(key) {
+        if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+          return;
+        }
+        var r = c[key] = (typeof c[key] === 'object') ?
+            c[key] : {ideal: c[key]};
+        if (r.min !== undefined ||
+            r.max !== undefined || r.exact !== undefined) {
+          require.push(key);
+        }
+        if (r.exact !== undefined) {
+          if (typeof r.exact === 'number') {
+            r. min = r.max = r.exact;
+          } else {
+            c[key] = r.exact;
+          }
+          delete r.exact;
+        }
+        if (r.ideal !== undefined) {
+          c.advanced = c.advanced || [];
+          var oc = {};
+          if (typeof r.ideal === 'number') {
+            oc[key] = {min: r.ideal, max: r.ideal};
+          } else {
+            oc[key] = r.ideal;
+          }
+          c.advanced.push(oc);
+          delete r.ideal;
+          if (!Object.keys(r).length) {
+            delete c[key];
+          }
+        }
+      });
+      if (require.length) {
+        c.require = require;
+      }
+      return c;
+    };
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (browserDetails.version < 38) {
+      logging('spec: ' + JSON.stringify(constraints));
+      if (constraints.audio) {
+        constraints.audio = constraintsToFF37_(constraints.audio);
+      }
+      if (constraints.video) {
+        constraints.video = constraintsToFF37_(constraints.video);
+      }
+      logging('ff37: ' + JSON.stringify(constraints));
+    }
+    return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
+      onError(shimError_(e));
+    });
+  };
+
+  // Returns the result of getUserMedia as a Promise.
+  var getUserMediaPromise_ = function(constraints) {
+    return new Promise(function(resolve, reject) {
+      getUserMedia_(constraints, resolve, reject);
+    });
+  };
+
+  // Shim for mediaDevices on older versions.
+  if (!navigator.mediaDevices) {
+    navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
+      addEventListener: function() { },
+      removeEventListener: function() { }
+    };
+  }
+  navigator.mediaDevices.enumerateDevices =
+      navigator.mediaDevices.enumerateDevices || function() {
+        return new Promise(function(resolve) {
+          var infos = [
+            {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
+            {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
+          ];
+          resolve(infos);
+        });
+      };
+
+  if (browserDetails.version < 41) {
+    // Work around http://bugzil.la/1169665
+    var orgEnumerateDevices =
+        navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
+    navigator.mediaDevices.enumerateDevices = function() {
+      return orgEnumerateDevices().then(undefined, function(e) {
+        if (e.name === 'NotFoundError') {
+          return [];
+        }
+        throw e;
+      });
+    };
+  }
+  if (browserDetails.version < 49) {
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      return origGetUserMedia(c).then(function(stream) {
+        // Work around https://bugzil.la/802326
+        if (c.audio && !stream.getAudioTracks().length ||
+            c.video && !stream.getVideoTracks().length) {
+          stream.getTracks().forEach(function(track) {
+            track.stop();
+          });
+          throw new DOMException('The object can not be found here.',
+                                 'NotFoundError');
+        }
+        return stream;
+      }, function(e) {
+        return Promise.reject(shimError_(e));
+      });
+    };
+  }
+  if (!(browserDetails.version > 55 &&
+      'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
+    var remap = function(obj, a, b) {
+      if (a in obj && !(b in obj)) {
+        obj[b] = obj[a];
+        delete obj[a];
+      }
+    };
+
+    var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
+        bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      if (typeof c === 'object' && typeof c.audio === 'object') {
+        c = JSON.parse(JSON.stringify(c));
+        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
+        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
+      }
+      return nativeGetUserMedia(c);
+    };
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
+      var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
+      MediaStreamTrack.prototype.getSettings = function() {
+        var obj = nativeGetSettings.apply(this, arguments);
+        remap(obj, 'mozAutoGainControl', 'autoGainControl');
+        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
+        return obj;
+      };
+    }
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
+      var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
+      MediaStreamTrack.prototype.applyConstraints = function(c) {
+        if (this.kind === 'audio' && typeof c === 'object') {
+          c = JSON.parse(JSON.stringify(c));
+          remap(c, 'autoGainControl', 'mozAutoGainControl');
+          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
+        }
+        return nativeApplyConstraints.apply(this, [c]);
+      };
+    }
+  }
+  navigator.getUserMedia = function(constraints, onSuccess, onError) {
+    if (browserDetails.version < 44) {
+      return getUserMedia_(constraints, onSuccess, onError);
+    }
+    // Replace Firefox 44+'s deprecation warning with unprefixed version.
+    utils.deprecated('navigator.getUserMedia',
+        'navigator.mediaDevices.getUserMedia');
+    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
+  };
+};
+
+},{"../utils":13}],12:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+'use strict';
+var utils = require('../utils');
+
+var safariShim = {
+  // TODO: DrAlex, should be here, double check against LayoutTests
+
+  // TODO: once the back-end for the mac port is done, add.
+  // TODO: check for webkitGTK+
+  // shimPeerConnection: function() { },
+
+  shimLocalStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getLocalStreams = function() {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        return this._localStreams;
+      };
+    }
+    if (!('getStreamById' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getStreamById = function(id) {
+        var result = null;
+        if (this._localStreams) {
+          this._localStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        if (this._remoteStreams) {
+          this._remoteStreams.forEach(function(stream) {
+            if (stream.id === id) {
+              result = stream;
+            }
+          });
+        }
+        return result;
+      };
+    }
+    if (!('addStream' in window.RTCPeerConnection.prototype)) {
+      var _addTrack = window.RTCPeerConnection.prototype.addTrack;
+      window.RTCPeerConnection.prototype.addStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        if (this._localStreams.indexOf(stream) === -1) {
+          this._localStreams.push(stream);
+        }
+        var self = this;
+        stream.getTracks().forEach(function(track) {
+          _addTrack.call(self, track, stream);
+        });
+      };
+
+      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
+        if (stream) {
+          if (!this._localStreams) {
+            this._localStreams = [stream];
+          } else if (this._localStreams.indexOf(stream) === -1) {
+            this._localStreams.push(stream);
+          }
+        }
+        return _addTrack.call(this, track, stream);
+      };
+    }
+    if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.removeStream = function(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        var index = this._localStreams.indexOf(stream);
+        if (index === -1) {
+          return;
+        }
+        this._localStreams.splice(index, 1);
+        var self = this;
+        var tracks = stream.getTracks();
+        this.getSenders().forEach(function(sender) {
+          if (tracks.indexOf(sender.track) !== -1) {
+            self.removeTrack(sender);
+          }
+        });
+      };
+    }
+  },
+  shimRemoteStreamsAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
+      window.RTCPeerConnection.prototype.getRemoteStreams = function() {
+        return this._remoteStreams ? this._remoteStreams : [];
+      };
+    }
+    if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
+      Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
+        get: function() {
+          return this._onaddstream;
+        },
+        set: function(f) {
+          if (this._onaddstream) {
+            this.removeEventListener('addstream', this._onaddstream);
+            this.removeEventListener('track', this._onaddstreampoly);
+          }
+          this.addEventListener('addstream', this._onaddstream = f);
+          this.addEventListener('track', this._onaddstreampoly = function(e) {
+            var stream = e.streams[0];
+            if (!this._remoteStreams) {
+              this._remoteStreams = [];
+            }
+            if (this._remoteStreams.indexOf(stream) >= 0) {
+              return;
+            }
+            this._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = e.streams[0];
+            this.dispatchEvent(event);
+          }.bind(this));
+        }
+      });
+    }
+  },
+  shimCallbacksAPI: function(window) {
+    if (typeof window !== 'object' || !window.RTCPeerConnection) {
+      return;
+    }
+    var prototype = window.RTCPeerConnection.prototype;
+    var createOffer = prototype.createOffer;
+    var createAnswer = prototype.createAnswer;
+    var setLocalDescription = prototype.setLocalDescription;
+    var setRemoteDescription = prototype.setRemoteDescription;
+    var addIceCandidate = prototype.addIceCandidate;
+
+    prototype.createOffer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createOffer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    prototype.createAnswer = function(successCallback, failureCallback) {
+      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      var promise = createAnswer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+    var withCallback = function(description, successCallback, failureCallback) {
+      var promise = setLocalDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setLocalDescription = withCallback;
+
+    withCallback = function(description, successCallback, failureCallback) {
+      var promise = setRemoteDescription.apply(this, [description]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.setRemoteDescription = withCallback;
+
+    withCallback = function(candidate, successCallback, failureCallback) {
+      var promise = addIceCandidate.apply(this, [candidate]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+    prototype.addIceCandidate = withCallback;
+  },
+  shimGetUserMedia: function(window) {
+    var navigator = window && window.navigator;
+
+    if (!navigator.getUserMedia) {
+      if (navigator.webkitGetUserMedia) {
+        navigator.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
+      } else if (navigator.mediaDevices &&
+          navigator.mediaDevices.getUserMedia) {
+        navigator.getUserMedia = function(constraints, cb, errcb) {
+          navigator.mediaDevices.getUserMedia(constraints)
+          .then(cb, errcb);
+        }.bind(navigator);
+      }
+    }
+  },
+  shimRTCIceServerUrls: function(window) {
+    // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+    var OrigPeerConnection = window.RTCPeerConnection;
+    window.RTCPeerConnection = function(pcConfig, pcConstraints) {
+      if (pcConfig && pcConfig.iceServers) {
+        var newIceServers = [];
+        for (var i = 0; i < pcConfig.iceServers.length; i++) {
+          var server = pcConfig.iceServers[i];
+          if (!server.hasOwnProperty('urls') &&
+              server.hasOwnProperty('url')) {
+            utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+            server = JSON.parse(JSON.stringify(server));
+            server.urls = server.url;
+            delete server.url;
+            newIceServers.push(server);
+          } else {
+            newIceServers.push(pcConfig.iceServers[i]);
+          }
+        }
+        pcConfig.iceServers = newIceServers;
+      }
+      return new OrigPeerConnection(pcConfig, pcConstraints);
+    };
+    window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+    // wrap static methods. Currently just generateCertificate.
+    if ('generateCertificate' in window.RTCPeerConnection) {
+      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+        get: function() {
+          return OrigPeerConnection.generateCertificate;
+        }
+      });
+    }
+  },
+  shimTrackEventTransceiver: function(window) {
+    // Add event.transceiver member over deprecated event.receiver
+    if (typeof window === 'object' && window.RTCPeerConnection &&
+        ('receiver' in window.RTCTrackEvent.prototype) &&
+        // can't check 'transceiver' in window.RTCTrackEvent.prototype, as it is
+        // defined for some reason even when window.RTCTransceiver is not.
+        !window.RTCTransceiver) {
+      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+        get: function() {
+          return {receiver: this.receiver};
+        }
+      });
+    }
+  },
+
+  shimCreateOfferLegacy: function(window) {
+    var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+    window.RTCPeerConnection.prototype.createOffer = function(offerOptions) {
+      var pc = this;
+      if (offerOptions) {
+        var audioTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'audio';
+        });
+        if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
+          if (audioTransceiver.direction === 'sendrecv') {
+            audioTransceiver.setDirection('sendonly');
+          } else if (audioTransceiver.direction === 'recvonly') {
+            audioTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveAudio === true &&
+            !audioTransceiver) {
+          pc.addTransceiver('audio');
+        }
+
+        var videoTransceiver = pc.getTransceivers().find(function(transceiver) {
+          return transceiver.sender.track &&
+              transceiver.sender.track.kind === 'video';
+        });
+        if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
+          if (videoTransceiver.direction === 'sendrecv') {
+            videoTransceiver.setDirection('sendonly');
+          } else if (videoTransceiver.direction === 'recvonly') {
+            videoTransceiver.setDirection('inactive');
+          }
+        } else if (offerOptions.offerToReceiveVideo === true &&
+            !videoTransceiver) {
+          pc.addTransceiver('video');
+        }
+      }
+      return origCreateOffer.apply(pc, arguments);
+    };
+  }
+};
+
+// Expose public methods.
+module.exports = {
+  shimCallbacksAPI: safariShim.shimCallbacksAPI,
+  shimLocalStreamsAPI: safariShim.shimLocalStreamsAPI,
+  shimRemoteStreamsAPI: safariShim.shimRemoteStreamsAPI,
+  shimGetUserMedia: safariShim.shimGetUserMedia,
+  shimRTCIceServerUrls: safariShim.shimRTCIceServerUrls,
+  shimTrackEventTransceiver: safariShim.shimTrackEventTransceiver,
+  shimCreateOfferLegacy: safariShim.shimCreateOfferLegacy
+  // TODO
+  // shimPeerConnection: safariShim.shimPeerConnection
+};
+
+},{"../utils":13}],13:[function(require,module,exports){
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+ /* eslint-env node */
+'use strict';
+
+var logDisabled_ = true;
+var deprecationWarnings_ = true;
+
+// Utility methods.
+var utils = {
+  disableLog: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    logDisabled_ = bool;
+    return (bool) ? 'adapter.js logging disabled' :
+        'adapter.js logging enabled';
+  },
+
+  /**
+   * Disable or enable deprecation warnings
+   * @param {!boolean} bool set to true to disable warnings.
+   */
+  disableWarnings: function(bool) {
+    if (typeof bool !== 'boolean') {
+      return new Error('Argument type: ' + typeof bool +
+          '. Please use a boolean.');
+    }
+    deprecationWarnings_ = !bool;
+    return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
+  },
+
+  log: function() {
+    if (typeof window === 'object') {
+      if (logDisabled_) {
+        return;
+      }
+      if (typeof console !== 'undefined' && typeof console.log === 'function') {
+        console.log.apply(console, arguments);
+      }
+    }
+  },
+
+  /**
+   * Shows a deprecation warning suggesting the modern and spec-compatible API.
+   */
+  deprecated: function(oldMethod, newMethod) {
+    if (!deprecationWarnings_) {
+      return;
+    }
+    console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
+        ' instead.');
+  },
+
+  /**
+   * Extract browser version out of the provided user agent string.
+   *
+   * @param {!string} uastring userAgent string.
+   * @param {!string} expr Regular expression used as match criteria.
+   * @param {!number} pos position in the version string to be returned.
+   * @return {!number} browser version.
+   */
+  extractVersion: function(uastring, expr, pos) {
+    var match = uastring.match(expr);
+    return match && match.length >= pos && parseInt(match[pos], 10);
+  },
+
+  /**
+   * Browser detector.
+   *
+   * @return {object} result containing browser and version
+   *     properties.
+   */
+  detectBrowser: function(window) {
+    var navigator = window && window.navigator;
+
+    // Returned result object.
+    var result = {};
+    result.browser = null;
+    result.version = null;
+
+    // Fail early if it's not a browser
+    if (typeof window === 'undefined' || !window.navigator) {
+      result.browser = 'Not a browser.';
+      return result;
+    }
+
+    // Firefox.
+    if (navigator.mozGetUserMedia) {
+      result.browser = 'firefox';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Firefox\/(\d+)\./, 1);
+    } else if (navigator.webkitGetUserMedia) {
+      // Chrome, Chromium, Webview, Opera, all use the chrome shim for now
+      if (window.webkitRTCPeerConnection) {
+        result.browser = 'chrome';
+        result.version = this.extractVersion(navigator.userAgent,
+          /Chrom(e|ium)\/(\d+)\./, 2);
+      } else { // Safari (in an unpublished version) or unknown webkit-based.
+        if (navigator.userAgent.match(/Version\/(\d+).(\d+)/)) {
+          result.browser = 'safari';
+          result.version = this.extractVersion(navigator.userAgent,
+            /AppleWebKit\/(\d+)\./, 1);
+        } else { // unknown webkit-based browser.
+          result.browser = 'Unsupported webkit-based browser ' +
+              'with GUM support but no WebRTC support.';
+          return result;
+        }
+      }
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) { // Edge.
+      result.browser = 'edge';
+      result.version = this.extractVersion(navigator.userAgent,
+          /Edge\/(\d+).(\d+)$/, 2);
+    } else if (navigator.mediaDevices &&
+        navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) {
+        // Safari, with webkitGetUserMedia removed.
+      result.browser = 'safari';
+      result.version = this.extractVersion(navigator.userAgent,
+          /AppleWebKit\/(\d+)\./, 1);
+    } else { // Default fallthrough: not supported.
+      result.browser = 'Not a supported browser.';
+      return result;
+    }
+
+    return result;
+  },
+
+};
+
+// Export.
+module.exports = {
+  log: utils.log,
+  deprecated: utils.deprecated,
+  disableLog: utils.disableLog,
+  disableWarnings: utils.disableWarnings,
+  extractVersion: utils.extractVersion,
+  shimCreateObjectURL: utils.shimCreateObjectURL,
+  detectBrowser: utils.detectBrowser.bind(utils)
+};
+
+},{}]},{},[3]);