Add metadata to media::VideoFrame and plumb it through IPC/MediaStream.

content/renderer/media/mock_media_stream_video_source.cc

Index: content/renderer/media/mock_media_stream_video_source.cc
diff --git a/content/renderer/media/mock_media_stream_video_source.cc b/content/renderer/media/mock_media_stream_video_source.cc
index 19f7b6f74d1f815817e33c037fffe4fecc562082..b99e4c31596e0513fe2b2e82685db6d137048d17 100644
--- a/content/renderer/media/mock_media_stream_video_source.cc
+++ b/content/renderer/media/mock_media_stream_video_source.cc
@@ -78,17 +78,7 @@ void MockMediaStreamVideoSource::DeliverVideoFrame(
   DCHECK(!frame_callback_.is_null());
   io_message_loop()->PostTask(
       FROM_HERE,
-      base::Bind(&MockMediaStreamVideoSource::DeliverVideoFrameOnIO,
-                 base::Unretained(this), frame, format_,
-                 base::TimeTicks(), frame_callback_));
-}
-
-void MockMediaStreamVideoSource::DeliverVideoFrameOnIO(
-    const scoped_refptr<media::VideoFrame>& frame,
-    media::VideoCaptureFormat format,
-    const base::TimeTicks& estimated_capture_time,
-    const VideoCaptureDeliverFrameCB& frame_callback) {
-  frame_callback.Run(frame, format, estimated_capture_time);
+      base::Bind(frame_callback_, frame, base::TimeTicks()));
 }
 
 }  // namespace content