Move the MediaObserver getter from ResourceContext to ContentBrowserClient, since we only need to s…

content/public/browser/media_observer.h

 // Copyright (c) 2012 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_PUBLIC_BROWSER_MEDIA_OBSERVER_H_
 #define CONTENT_PUBLIC_BROWSER_MEDIA_OBSERVER_H_
 #pragma once
 
 namespace media {
 struct MediaLogEvent;
 }
 
 namespace content {
 
-// A class may implement MediaObserver and register itself with ResourceContext
-// to receive callbacks as media events occur.
+// An embedder may implement MediaObserver and return it from
+// ContentBrowserClient to receive callbacks as media events occur.
 class MediaObserver {
  public:
   // Called when an audio stream is deleted.
   virtual void OnDeleteAudioStream(void* host, int stream_id) = 0;
 
   // Called when an audio stream is set to playing or paused.
   virtual void OnSetAudioStreamPlaying(void* host, int stream_id,
                                        bool playing) = 0;
 
   // Called when the status of an audio stream is set to "created", "flushed",
   // "closed", or "error".
   virtual void OnSetAudioStreamStatus(void* host, int stream_id,
                                       const std::string& status) = 0;
 
   // Called when the volume of an audio stream is set.
   virtual void OnSetAudioStreamVolume(void* host, int stream_id,
                                       double volume) = 0;
 
   // Called when a MediaEvent occurs.
   virtual void OnMediaEvent(int render_process_id,
                             const media::MediaLogEvent& event) = 0;
 
  protected:
   virtual ~MediaObserver() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_MEDIA_OBSERVER_H_