Make MediaPlayerEventRouter a PKS to decouple it from ExtensionService

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;
+
+namespace extensions {
 
 // Event router class for events related to Mediaplayer.
-class ExtensionMediaPlayerEventRouter {
+class MediaPlayerEventRouter {
  public:
-  static ExtensionMediaPlayerEventRouter* GetInstance();
-
-  void Init(Profile* profile);
+  explicit MediaPlayerEventRouter(Profile* profile);
+  virtual ~MediaPlayerEventRouter();
 
   // 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);
+  DISALLOW_COPY_AND_ASSIGN(MediaPlayerEventRouter);
 };
 
+}  // namespace extensions
+
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_MEDIA_PLAYER_EVENT_ROUTER_H_