Implement MediaStreamTrack contentHint skeleton.

content/renderer/media/media_stream_video_track.cc

 // 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.
 
 #include "content/renderer/media/media_stream_video_track.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 265 matching lines @@
                                      secure_tracker_.is_capturing_secure());
 }
 
 void MediaStreamVideoTrack::SetEnabled(bool enabled) {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
   frame_deliverer_->SetEnabled(enabled);
   for (auto* sink : sinks_)
     sink->OnEnabledChanged(enabled);
 }
 
+void MediaStreamVideoTrack::SetContentHint(
+    blink::WebMediaStreamTrack::ContentHintType content_hint) {
+  DCHECK(main_render_thread_checker_.CalledOnValidThread());
+  for (auto* sink : sinks_)
+    sink->OnContentHintChanged(content_hint);
+}
+
 void MediaStreamVideoTrack::Stop() {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
   if (source_) {
     source_->RemoveTrack(this);
     source_ = NULL;
   }
   OnReadyStateChanged(blink::WebMediaStreamSource::ReadyStateEnded);
 }
 
 void MediaStreamVideoTrack::getSettings(
@@ skipping 11 matching lines @@
 }
 
 void MediaStreamVideoTrack::OnReadyStateChanged(
     blink::WebMediaStreamSource::ReadyState state) {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
   for (auto* sink : sinks_)
     sink->OnReadyStateChanged(state);
 }
 
 }  // namespace content