Revert of Revert of Propagate audible state from player to the containing tab"

content/browser/media/media_web_contents_observer.h

 // Copyright 2014 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_BROWSER_MEDIA_MEDIA_WEB_CONTENTS_OBSERVER_H_
 #define CONTENT_BROWSER_MEDIA_MEDIA_WEB_CONTENTS_OBSERVER_H_
 
 #include "base/compiler_specific.h"
 #include "base/containers/scoped_ptr_hash_map.h"
+#include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/web_contents_observer.h"
 
 namespace content {
 
+#if defined(OS_ANDROID)
+class MediaPlayersObserver;
+#endif  // defined(OS_ANDROID)
+
 class BrowserCdmManager;
 class BrowserMediaPlayerManager;
 
 // This class manages all RenderFrame based media related managers at the
 // browser side. It receives IPC messages from media RenderFrameObservers and
 // forwards them to the corresponding managers. The managers are responsible
 // for sending IPCs back to the RenderFrameObservers at the render side.
 class CONTENT_EXPORT MediaWebContentsObserver : public WebContentsObserver {
  public:
   explicit MediaWebContentsObserver(WebContents* web_contents);
@@ skipping 13 matching lines @@
   bool OnMediaPlayerSetCdmMessageReceived(const IPC::Message& message,
                                           RenderFrameHost* render_frame_host);
 
   // Gets the media player manager associated with |render_frame_host|. Creates
   // a new one if it doesn't exist. The caller doesn't own the returned pointer.
   BrowserMediaPlayerManager* GetMediaPlayerManager(
       RenderFrameHost* render_frame_host);
 
   void OnSetCdm(RenderFrameHost* render_frame_host, int player_id, int cdm_id);
 
+  MediaPlayersObserver* GetMediaPlayersObserver() const;
+
 #if defined(VIDEO_HOLE)
   void OnFrameInfoUpdated();
 #endif  // defined(VIDEO_HOLE)
 
  private:
   // Map from RenderFrameHost* to BrowserMediaPlayerManager.
   typedef base::ScopedPtrHashMap<uintptr_t, BrowserMediaPlayerManager>
       MediaPlayerManagerMap;
   MediaPlayerManagerMap media_player_managers_;
 #endif  // defined(OS_ANDROID)
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MediaWebContentsObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_MEDIA_WEB_CONTENTS_OBSERVER_H_