MediaStreamVideo*/VideoTrackAdapter and RTCVideoRenderer (small) cleanup

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 41 matching lines @@
   void SetEnabled(bool enabled) override;
 
   void Stop() override;
 
   void OnReadyStateChanged(blink::WebMediaStreamSource::ReadyState state);
 
   const blink::WebMediaConstraints& constraints() const {
     return constraints_;
   }
 
- protected:
-  // Used to DCHECK that we are called on the correct thread.
-  base::ThreadChecker thread_checker_;
-
  private:
   // MediaStreamVideoSink is a friend to allow it to call AddSink() and
   // RemoveSink().
   friend class MediaStreamVideoSink;
   FRIEND_TEST_ALL_PREFIXES(MediaStreamRemoteVideoSourceTest, StartTrack);
   FRIEND_TEST_ALL_PREFIXES(MediaStreamRemoteVideoSourceTest, RemoteTrackStop);
   FRIEND_TEST_ALL_PREFIXES(VideoDestinationHandlerTest, PutFrame);
 
   // Add |sink| to receive state changes on the main render thread and video
   // frames in the |callback| method on the IO-thread.
   // |callback| will be reset on the render thread.
   // These two methods are private such that no subclass can intercept and
   // store the callback. This is important to ensure that we can release
   // the callback on render thread without reference to it on the IO-thread.
   void AddSink(MediaStreamVideoSink* sink,
                const VideoCaptureDeliverFrameCB& callback);
   void RemoveSink(MediaStreamVideoSink* sink);
 
   std::vector<MediaStreamVideoSink*> sinks_;
 
   // |FrameDeliverer| is an internal helper object used for delivering video
   // frames on the IO-thread using callbacks to all registered tracks.
   class FrameDeliverer;
-  scoped_refptr<FrameDeliverer> frame_deliverer_;
+  const scoped_refptr<FrameDeliverer> frame_deliverer_;
 
-  blink::WebMediaConstraints constraints_;
+  const blink::WebMediaConstraints constraints_;
 
   // Weak ref to the source this tracks is connected to.  |source_| is owned
   // 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_