Implement MediaStreamTrack contentHint skeleton.

content/renderer/media/media_stream_audio_track.h

 // Copyright 2015 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_AUDIO_TRACK_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_TRACK_H_
 
 #include <memory>
 
 #include "base/atomicops.h"
@@ skipping 47 matching lines @@
   // to the complexity of all types of audio tracks+source implementations.
   // http://crbug.com/577874
   media::AudioParameters GetOutputFormat() const;
 
   // Halts the flow of audio data from the source (and to the sinks), and then
   // notifies all sinks of the "ended" state.
   void Stop() final;
 
   // MediaStreamTrack override.
   void SetEnabled(bool enabled) override;
+  void SetContentHint(
+      blink::WebMediaStreamTrack::ContentHintType content_hint) override;
 
   // Returns a unique class identifier. Some subclasses override and use this
   // method to provide safe down-casting to their type.
   virtual void* GetClassIdentifier() const;
 
  private:
   friend class MediaStreamAudioSource;
   friend class MediaStreamAudioDeliverer<MediaStreamAudioTrack>;
 
   // Called by MediaStreamAudioSource to notify this track that the flow of
@@ skipping 33 matching lines @@
 
   // Provides weak pointers that are valid until Stop() is called.
   base::WeakPtrFactory<MediaStreamAudioTrack> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamAudioTrack);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_TRACK_H_