AcceleratorProvider: Make GetAcceleratorForCommandId const.

chrome/browser/ui/app_list/app_context_menu.h

 // Copyright 2013 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_APP_LIST_APP_CONTEXT_MENU_H_
 #define CHROME_BROWSER_UI_APP_LIST_APP_CONTEXT_MENU_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 34 matching lines @@
 
   // Note this could return nullptr if corresponding app item is gone.
   virtual ui::MenuModel* GetMenuModel();
 
   // ui::SimpleMenuModel::Delegate overrides:
   bool IsItemForCommandIdDynamic(int command_id) const override;
   base::string16 GetLabelForCommandId(int command_id) const override;
   bool IsCommandIdChecked(int command_id) const override;
   bool IsCommandIdEnabled(int command_id) const override;
   bool GetAcceleratorForCommandId(int command_id,
-                                  ui::Accelerator* accelerator) override;
+                                  ui::Accelerator* accelerator) const override;
   void ExecuteCommand(int command_id, int event_flags) override;
 
  protected:
   AppContextMenu(AppContextMenuDelegate* delegate,
                  Profile* profile,
                  const std::string& app_id,
                  AppListControllerDelegate* controller);
 
   // Creates default items, derived class may override to add their specific
   // items.
@@ skipping 14 matching lines @@
   AppListControllerDelegate* controller_;
 
   std::unique_ptr<ui::SimpleMenuModel> menu_model_;
 
   DISALLOW_COPY_AND_ASSIGN(AppContextMenu);
 };
 
 }  // namespace app_list
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_APP_CONTEXT_MENU_H_