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

ash/shell/shell_delegate_impl.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 ASH_SHELL_SHELL_DELEGATE_IMPL_H_
 #define ASH_SHELL_SHELL_DELEGATE_IMPL_H_
 
 #include "ash/shell_delegate.h"
 #include "base/compiler_specific.h"
 
@@ skipping 31 matching lines @@
   virtual bool IsSpokenFeedbackEnabled() const OVERRIDE;
   virtual app_list::AppListViewDelegate* CreateAppListViewDelegate() OVERRIDE;
   virtual ash::LauncherDelegate* CreateLauncherDelegate(
       ash::LauncherModel* model) OVERRIDE;
   virtual ash::SystemTrayDelegate* CreateSystemTrayDelegate(
       ash::SystemTray* tray) OVERRIDE;
   virtual ash::UserWallpaperDelegate* CreateUserWallpaperDelegate() OVERRIDE;
   virtual aura::client::UserActionClient* CreateUserActionClient() OVERRIDE;
   virtual void OpenFeedbackPage() OVERRIDE;
   virtual void RecordUserMetricsAction(UserMetricsAction action) OVERRIDE;
+  virtual void HandleMediaNextTrack() OVERRIDE;
+  virtual void HandleMediaPlayPause() OVERRIDE;
+  virtual void HandleMediaPrevTrack() OVERRIDE;
 
  private:
   // Used to update Launcher. Owned by main.
   WindowWatcher* watcher_;
 
   LauncherDelegateImpl* launcher_delegate_;
 
   bool locked_;
   bool spoken_feedback_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellDelegateImpl);
 };
 
 }  // namespace shell
 }  // namespace ash
 
 #endif  // ASH_SHELL_SHELL_DELEGATE_IMPL_H_