Ash: Support "Next Song", "Previous Song", "Play/Pause" Multi Media buttons

chrome/browser/chromeos/extensions/media_player_event_router.h

 // Copyright (c) 2011 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 CHROME_BROWSER_CHROMEOS_EXTENSIONS_MEDIA_PLAYER_EVENT_ROUTER_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_MEDIA_PLAYER_EVENT_ROUTER_H_
 
 #include "base/basictypes.h"
 
 class Profile;
 template <typename T> struct DefaultSingletonTraits;
 
 // Event router class for events related to Mediaplayer.
 class ExtensionMediaPlayerEventRouter {
  public:
   static ExtensionMediaPlayerEventRouter* GetInstance();
 
   void Init(Profile* profile);
 
+  // Send notification that next-track shortcut key was pressed.
+  void NotifyNextTrack();
+
+  // Send notification that playlist changed.
   void NotifyPlaylistChanged();
 
+  // Send notification that previous-track shortcut key was pressed.
+  void NotifyPrevTrack();
+
+  // Send notification that play/pause shortcut key was pressed.
+  void NotifyTogglePlayState();
+
  private:
   Profile* profile_;
 
   ExtensionMediaPlayerEventRouter();
   friend struct DefaultSingletonTraits<ExtensionMediaPlayerEventRouter>;
   DISALLOW_COPY_AND_ASSIGN(ExtensionMediaPlayerEventRouter);
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_MEDIA_PLAYER_EVENT_ROUTER_H_