Update MediaStreamTrack::Stop to latest draft.

content/renderer/media/media_stream_center.cc

Index: content/renderer/media/media_stream_center.cc
diff --git a/content/renderer/media/media_stream_center.cc b/content/renderer/media/media_stream_center.cc
index d7279c7d47046c3aaf99296949ff8cb001778a06..2334ad2a7279d4e0796cd199fbdd8985b210116c 100644
--- a/content/renderer/media/media_stream_center.cc
+++ b/content/renderer/media/media_stream_center.cc
@@ -121,15 +121,8 @@ void MediaStreamCenter::didDisableMediaStreamTrack(
 bool MediaStreamCenter::didStopMediaStreamTrack(
     const blink::WebMediaStreamTrack& track) {
   DVLOG(1) << "MediaStreamCenter::didStopMediaStreamTrack";
-  blink::WebMediaStreamSource source = track.source();
-  MediaStreamSource* extra_data =
-      static_cast<MediaStreamSource*>(source.extraData());
-  if (!extra_data) {
-    DVLOG(1) << "didStopMediaStreamTrack called on a remote track.";
-    return false;
-  }
-
-  extra_data->StopSource();
+  MediaStreamTrack* native_track = MediaStreamTrack::GetTrack(track);
+  native_track->Stop();
   return true;
 }
 
@@ -163,22 +156,16 @@ void MediaStreamCenter::didStopLocalMediaStream(
   }
 
   // TODO(perkj): MediaStream::Stop is being deprecated. But for the moment we
-  // need to support the old behavior and the new. Since we only create one
-  // source object per actual device- we need to fake stopping a
-  // MediaStreamTrack by disabling it if the same device is used as source by
-  // multiple tracks. Note that disabling a track here, don't affect the
-  // enabled property in JS.
+  // need to support both MediaStream::Stop and MediaStreamTrack::Stop.
   blink::WebVector<blink::WebMediaStreamTrack> audio_tracks;
   stream.audioTracks(audio_tracks);
   for (size_t i = 0; i < audio_tracks.size(); ++i)
-    didDisableMediaStreamTrack(audio_tracks[i]);
+    didStopMediaStreamTrack(audio_tracks[i]);
 
   blink::WebVector<blink::WebMediaStreamTrack> video_tracks;
   stream.videoTracks(video_tracks);
   for (size_t i = 0; i < video_tracks.size(); ++i)
-    didDisableMediaStreamTrack(video_tracks[i]);
-
-  native_stream->OnStreamStopped();
+    didStopMediaStreamTrack(video_tracks[i]);
 }
 
 void MediaStreamCenter::didCreateMediaStream(blink::WebMediaStream& stream) {
@@ -186,7 +173,6 @@ void MediaStreamCenter::didCreateMediaStream(blink::WebMediaStream& stream) {
   blink::WebMediaStream writable_stream(stream);
   MediaStream* native_stream(
       new MediaStream(rtc_factory_,
-                      MediaStream::StreamStopCallback(),
                       stream));
   writable_stream.setExtraData(native_stream);