Update idl files in third_party/WebCore

Modules/mediastream/RTCPeerConnection.idl

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 50 matching lines @@
         raises(DOMException);
 
     void addIceCandidate(in RTCIceCandidate candidate)
         raises(DOMException);
 
     readonly attribute DOMString iceGatheringState;
     readonly attribute DOMString iceConnectionState;
 
     sequence<MediaStream> getLocalStreams();
     sequence<MediaStream> getRemoteStreams();
+    MediaStream getStreamById(DOMString streamId);
 
     [StrictTypeChecking] void addStream(in MediaStream stream, in [Optional] Dictionary mediaConstraints)
         raises(DOMException);
     [StrictTypeChecking] void removeStream(in MediaStream stream)
         raises(DOMException);
 
     void getStats(in [Callback] RTCStatsCallback successCallback, in [Optional=DefaultIsUndefined] MediaStreamTrack selector);
 
     RTCDataChannel createDataChannel(in [TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString label, in [Optional] Dictionary options)
          raises(DOMException);
@@ skipping 17 matching lines @@
     void addEventListener(in DOMString type,
                           in EventListener listener,
                           in [Optional] boolean useCapture);
     void removeEventListener(in DOMString type,
                              in EventListener listener,
                              in [Optional] boolean useCapture);
     boolean dispatchEvent(in Event event)
         raises(EventException);
 };