Implement a source for remote video tracks.

content/renderer/media/mock_media_stream_dependency_factory.h

Index: content/renderer/media/mock_media_stream_dependency_factory.h
diff --git a/content/renderer/media/mock_media_stream_dependency_factory.h b/content/renderer/media/mock_media_stream_dependency_factory.h
index 05cd5c7d1754157febba8a3dbcadbafa3d64c4aa..a2cce87c123813f2affa3b39cdf358314a0b4fb4 100644
--- a/content/renderer/media/mock_media_stream_dependency_factory.h
+++ b/content/renderer/media/mock_media_stream_dependency_factory.h
@@ -104,9 +104,9 @@ class MockAudioSource : public webrtc::AudioSourceInterface {
   webrtc::MediaConstraintsInterface::Constraints mandatory_constraints_;
 };
 
-class MockLocalVideoTrack : public webrtc::VideoTrackInterface {
+class MockWebRtcVideoTrack : public webrtc::VideoTrackInterface {
  public:
-  MockLocalVideoTrack(std::string id,
+  MockWebRtcVideoTrack(std::string id,
                       webrtc::VideoSourceInterface* source);
   virtual void AddRenderer(webrtc::VideoRendererInterface* renderer) OVERRIDE;
   virtual void RemoveRenderer(
@@ -122,7 +122,7 @@ class MockLocalVideoTrack : public webrtc::VideoTrackInterface {
   virtual webrtc::VideoSourceInterface* GetSource() const OVERRIDE;
 
  protected:
-  virtual ~MockLocalVideoTrack();
+  virtual ~MockWebRtcVideoTrack();
 
  private:
   bool enabled_;
@@ -130,6 +130,7 @@ class MockLocalVideoTrack : public webrtc::VideoTrackInterface {
   TrackState state_;
   scoped_refptr<webrtc::VideoSourceInterface> source_;
   webrtc::ObserverInterface* observer_;
+  webrtc::VideoRendererInterface* renderer_;
 };
 
 class MockMediaStream : public webrtc::MediaStreamInterface {