chrome: Cleanup class/struct forward declarations

chrome/browser/ui/ash/launcher/arc_launcher_context_menu.h

 // Copyright 2016 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_UI_ASH_LAUNCHER_ARC_LAUNCHER_CONTEXT_MENU_H_
 #define CHROME_BROWSER_UI_ASH_LAUNCHER_ARC_LAUNCHER_CONTEXT_MENU_H_
 
 #include "base/macros.h"
 #include "chrome/browser/ui/ash/launcher/launcher_context_menu.h"
 
-class ChromeLauncherController;
-
 namespace ash {
 struct ShelfItem;
 class WmShelf;
 }
 
 // Class for context menu which is shown for Arc app in the shelf.
 class ArcLauncherContextMenu : public LauncherContextMenu {
  public:
   ArcLauncherContextMenu(ChromeLauncherControllerImpl* controller,
                          const ash::ShelfItem* item,
                          ash::WmShelf* wm_shelf);
   ~ArcLauncherContextMenu() override;
 
   // ui::SimpleMenuModel::Delegate overrides:
   bool IsCommandIdEnabled(int command_id) const override;
 
  private:
   void Init();
 
   DISALLOW_COPY_AND_ASSIGN(ArcLauncherContextMenu);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_LAUNCHER_ARC_LAUNCHER_CONTEXT_MENU_H_