AcceleratorProvider: Make GetAcceleratorForCommandId const.

ui/views/touchui/touch_selection_controller_impl_unittest.cc

 // 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.
 
 #include <stddef.h>
 
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/aura/client/screen_position_client.h"
@@ skipping 670 matching lines @@
   // Overridden from ui::SimpleMenuModel::Delegate.
   bool IsCommandIdChecked(int command_id) const override {
     NOTREACHED();
     return false;
   }
   bool IsCommandIdEnabled(int command_id) const override {
     NOTREACHED();
     return false;
   }
   bool GetAcceleratorForCommandId(int command_id,
-                                  ui::Accelerator* accelerator) override {
+                                  ui::Accelerator* accelerator) const override {
     NOTREACHED();
     return false;
   }
   void ExecuteCommand(int command_id, int event_flags) override {
     NOTREACHED();
   }
 
   aura::Window* window_;
 
   // Boundaries of the client view.
@@ skipping 166 matching lines @@
   // Start touch editing; then press a key and ensure it deactivates touch
   // selection.
   StartTouchEditing();
   EXPECT_TRUE(GetSelectionController());
   generator.PressKey(ui::VKEY_A, 0);
   RunPendingMessages();
   EXPECT_FALSE(GetSelectionController());
 }
 
 }  // namespace views