Refactor VideoTracks to forward all sinks to its source

webrtc/api/videotrack.h

Index: webrtc/api/videotrack.h
diff --git a/webrtc/api/videotrack.h b/webrtc/api/videotrack.h
index 3a59504a38cbb6e2d96204c6b683ce3133e97db4..39400a371588b7b0d3d344d5aed958e72b2146f7 100644
--- a/webrtc/api/videotrack.h
+++ b/webrtc/api/videotrack.h
@@ -12,11 +12,13 @@
 #define WEBRTC_API_VIDEOTRACK_H_
 
 #include <string>
+#include <vector>
 
 #include "webrtc/api/mediastreamtrack.h"
 #include "webrtc/api/videosourceinterface.h"
 #include "webrtc/api/videotrackrenderers.h"
 #include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/thread_checker.h"
 
 namespace webrtc {
 
@@ -41,7 +43,19 @@ class VideoTrack : public MediaStreamTrack<VideoTrackInterface> {
   ~VideoTrack();
 
  private:
-  VideoTrackRenderers renderers_;
+  struct SinkPair {
+    SinkPair(rtc::VideoSinkInterface<cricket::VideoFrame>* sink,
+             rtc::VideoSinkWants wants)
+        : sink(sink), wants(wants) {}
+    rtc::VideoSinkInterface<cricket::VideoFrame>* sink;
+    rtc::VideoSinkWants wants;
+  };
+  SinkPair* FindSinkPair(
+      const rtc::VideoSinkInterface<cricket::VideoFrame>* sink);
+
+  rtc::ThreadChecker thread_checker_;
+  std::vector<SinkPair> sinks_;
+
   rtc::scoped_refptr<VideoTrackSourceInterface> video_source_;
 };