Make VideoTrack and VideoTrackRenderers implement rtc::VideoSourceInterface.

webrtc/api/videotrack.h

Index: webrtc/api/videotrack.h
diff --git a/webrtc/api/videotrack.h b/webrtc/api/videotrack.h
index f2b8f19c5bd2ec7678f5d5795809e72bc968c5d3..42f9450c383a38de2d937de946c8079f4143ea56 100644
--- a/webrtc/api/videotrack.h
+++ b/webrtc/api/videotrack.h
@@ -23,10 +23,13 @@ namespace webrtc {
 class VideoTrack : public MediaStreamTrack<VideoTrackInterface> {
  public:
   static rtc::scoped_refptr<VideoTrack> Create(
-      const std::string& label, VideoSourceInterface* source);
+      const std::string& label,
+      VideoSourceInterface* source);
+
+  void AddOrUpdateSink(rtc::VideoSinkInterface<cricket::VideoFrame>* sink,
+                       const rtc::VideoSinkWants& wants) override;
+  void RemoveSink(rtc::VideoSinkInterface<cricket::VideoFrame>* sink) override;
 
-  virtual void AddRenderer(VideoRendererInterface* renderer);
-  virtual void RemoveRenderer(VideoRendererInterface* renderer);
   virtual VideoSourceInterface* GetSource() const {
     return video_source_.get();
   }