Add video frame refresh to MediaStream and VideoCapture stacks.

content/renderer/media/media_stream_video_track.h

 // Copyright 2013 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 CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 33 matching lines @@
   // Constructor for video tracks.
   MediaStreamVideoTrack(
       MediaStreamVideoSource* source,
       const blink::WebMediaConstraints& constraints,
       const MediaStreamVideoSource::ConstraintsCallback& callback,
       bool enabled);
   ~MediaStreamVideoTrack() override;
 
   void SetEnabled(bool enabled) override;
 
+  // Requests the source send a frame "soon" (e.g., to resolve picture loss or
+  // quality issues).
+  void RequestRefreshFrame();

[xjz, 2016/04/05 00:04:43]

nit: move this after the implementation of MediaStreamTrack, i.e., after stop()?

[miu, 2016/04/05 20:25:01]

Done.

+
   void Stop() override;
 
   void OnReadyStateChanged(blink::WebMediaStreamSource::ReadyState state);
 
   const blink::WebMediaConstraints& constraints() const { return constraints_; }
 
  private:
   // MediaStreamVideoSink is a friend to allow it to call AddSink() and
   // RemoveSink().
   friend class MediaStreamVideoSink;
@@ skipping 24 matching lines @@
   // by the blink::WebMediaStreamSource and is guaranteed to outlive the
   // track.
   MediaStreamVideoSource* source_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoTrack);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_