Implement MediaStreamTrack contentHint skeleton.

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 34 matching lines @@
   // Constructor for video tracks.
   MediaStreamVideoTrack(
       MediaStreamVideoSource* source,
       const blink::WebMediaConstraints& constraints,
       const MediaStreamVideoSource::ConstraintsCallback& callback,
       bool enabled);
   ~MediaStreamVideoTrack() override;
 
   // MediaStreamTrack overrides.
   void SetEnabled(bool enabled) override;
+  void SetContentHint(
+      blink::WebMediaStreamTrack::ContentHintType content_hint) override;
   void Stop() override;
   void getSettings(blink::WebMediaStreamTrack::Settings& settings) 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().
@@ skipping 27 matching lines @@
 
   // This is used for tracking if all connected video sinks are secure.
   SecureDisplayLinkTracker<MediaStreamVideoSink> secure_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoTrack);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_