Add support for content hints to VideoTrack.

webrtc/api/mediastreamtrackproxy.h

 /*
  *  Copyright 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 23 matching lines @@
   PROXY_METHOD1(void, RegisterObserver, ObserverInterface*)
   PROXY_METHOD1(void, UnregisterObserver, ObserverInterface*)
 END_SIGNALING_PROXY()
 
 BEGIN_PROXY_MAP(VideoTrack)
   PROXY_CONSTMETHOD0(std::string, kind)
   PROXY_CONSTMETHOD0(std::string, id)
   PROXY_CONSTMETHOD0(TrackState, state)
   PROXY_CONSTMETHOD0(bool, enabled)
   PROXY_METHOD1(bool, set_enabled, bool)
+  PROXY_CONSTMETHOD0(ContentHint, content_hint)
+  PROXY_METHOD1(void, set_content_hint, ContentHint)
   PROXY_WORKER_METHOD2(void,
                        AddOrUpdateSink,
                        rtc::VideoSinkInterface<VideoFrame>*,
                        const rtc::VideoSinkWants&)
   PROXY_WORKER_METHOD1(void, RemoveSink, rtc::VideoSinkInterface<VideoFrame>*)
   PROXY_CONSTMETHOD0(VideoTrackSourceInterface*, GetSource)
 
   PROXY_METHOD1(void, RegisterObserver, ObserverInterface*)
   PROXY_METHOD1(void, UnregisterObserver, ObserverInterface*)
 END_PROXY()
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_MEDIASTREAMTRACKPROXY_H_