Added VideoTrackInterface::GetSink method, for use by VideoRtpReceiver. Get rid of FrameInput.

talk/app/webrtc/mediastreaminterface.h

Index: talk/app/webrtc/mediastreaminterface.h
diff --git a/talk/app/webrtc/mediastreaminterface.h b/talk/app/webrtc/mediastreaminterface.h
index 8d6feb02ef268a8115985d517e13cd0a40a018a3..4edf4ac6fc1c710dc11db3b12c4439ae7428d200 100644
--- a/talk/app/webrtc/mediastreaminterface.h
+++ b/talk/app/webrtc/mediastreaminterface.h
@@ -146,6 +146,7 @@ class VideoTrackInterface : public MediaStreamTrackInterface {
   virtual void RemoveRenderer(VideoRendererInterface* renderer) = 0;
 
   virtual VideoSourceInterface* GetSource() const = 0;

[pthatcher1, 2016/02/03 16:24:29]

As mentioned in the other CL, I think we can just have VideoTrackInterface
implement rtc::VideoSinkInterface<cricket::VideoFrame> and then we don't need
GetSink() and we can just use a VideoTrackInterface as a sink.

+  virtual rtc::VideoSinkInterface<cricket::VideoFrame>* GetSink() = 0;
 
  protected:
   virtual ~VideoTrackInterface() {}