Implement and use VideoTrackSource directly.

content/renderer/media/webrtc/media_stream_video_webrtc_sink.h

 // Copyright 2014 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_WEBRTC_WEBRTC_VIDEO_TRACK_ADAPTER_H_
 #define CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_TRACK_ADAPTER_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
@@ skipping 31 matching lines @@
   void OnEnabledChanged(bool enabled) override;
 
  private:
   // Helper to request a refresh frame from the source. Called via the callback
   // passed to WebRtcVideoSourceAdapter.
   void RequestRefreshFrame();
 
   // Used to DCHECK that we are called on the correct thread.
   base::ThreadChecker thread_checker_;
 
+  // |video_source_| and |video_track_source_proxy_| are held as references to
+  // outlive |video_track_| since the interfaces between them don't use
+  // reference counting.
+  class WebRtcVideoSource;
+  scoped_refptr<WebRtcVideoSource> video_source_;
+  scoped_refptr<webrtc::VideoTrackSourceInterface> video_source_proxy_;
   scoped_refptr<webrtc::VideoTrackInterface> video_track_;
 
   class WebRtcVideoSourceAdapter;
   scoped_refptr<WebRtcVideoSourceAdapter> source_adapter_;
 
   // Provides WebRtcVideoSourceAdapter a weak reference to
   // MediaStreamVideoWebRtcSink in order to allow it to request refresh frames.
   // See comments in media_stream_video_webrtc_sink.cc.
   base::WeakPtrFactory<MediaStreamVideoWebRtcSink> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoWebRtcSink);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_TRACK_ADAPTER_H_