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

media/base/video_capturer_source.h

Index: media/base/video_capturer_source.h
diff --git a/media/base/video_capturer_source.h b/media/base/video_capturer_source.h
index 56ec7296a9b9a89021e88b2d7c3ee5cf5fbd5f96..774f28da02faf97e188a1eaffc5e5308b877c764 100644
--- a/media/base/video_capturer_source.h
+++ b/media/base/video_capturer_source.h
@@ -42,7 +42,6 @@ class MEDIA_EXPORT VideoCapturerSource {
   // the first video frame delivered may not have timestamp equal to 0.
   typedef base::Callback<
    void(const scoped_refptr<media::VideoFrame>& video_frame,
-        const media::VideoCaptureFormat& format,
         const base::TimeTicks& estimated_capture_time)>
       VideoCaptureDeliverFrameCB;