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

media/base/video_capturer_source.h

 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURER_SOURCE_H_
 #define MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURER_SOURCE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 24 matching lines @@
   // presentation time; but, instead, it should be used for buffering playback
   // and for A/V synchronization purposes. NOTE: It is possible for this value
   // to be null if the current implementation lacks this timing information.
   //
   // |video_frame->timestamp()| gives the presentation timestamp of the video
   // frame relative to the first frame generated by the corresponding source.
   // Because a source can start generating frames before a subscriber is added,
   // 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;
 
   typedef base::Callback<void(const media::VideoCaptureFormats&)>
       VideoCaptureDeviceFormatsCB;
 
   typedef base::Callback<void(bool)> RunningCallback;
 
   // Collects the formats that can currently be used.
   // |max_requested_height|, |max_requested_width|, and
@@ skipping 26 matching lines @@
   // Stops capturing frames and clears all callbacks including the
   // SupportedFormatsCallback callback. Note that queued frame callbacks
   // may still occur after this call, so the caller must take care to
   // use refcounted or weak references in |new_frame_callback|.
   virtual void StopCapture() = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURER_SOURCE_H_