chromeos: Show deprecated accelerator notifications in mash

ash/accelerators/accelerator_controller_delegate_aura.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 ASH_ACCELERATORS_ACCELERATOR_HANDLER_AURA_H_
 #define ASH_ACCELERATORS_ACCELERATOR_HANDLER_AURA_H_
 
 #include <memory>
 
 #include "ash/common/accelerators/accelerator_controller_delegate.h"
@@ skipping 18 matching lines @@
     return screenshot_delegate_.get();
   }
 
   // AcceleratorControllerDelegate:
   bool HandlesAction(AcceleratorAction action) override;
   bool CanPerformAction(AcceleratorAction action,
                         const ui::Accelerator& accelerator,
                         const ui::Accelerator& previous_accelerator) override;
   void PerformAction(AcceleratorAction action,
                      const ui::Accelerator& accelerator) override;
-  void ShowDeprecatedAcceleratorNotification(const char* const notification_id,
-                                             int message_id,
-                                             int old_shortcut_id,
-                                             int new_shortcut_id) override;
 
  private:
   std::unique_ptr<ScreenshotDelegate> screenshot_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(AcceleratorControllerDelegateAura);
 };
 
 }  // namespace ash
 
 #endif  // ASH_ACCELERATORS_ACCELERATOR_HANDLER_AURA_H_