AcceleratorProvider: Make GetAcceleratorForCommandId const.

ui/views/examples/menu_example.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 "ui/views/examples/menu_example.h"
 
 #include <set>
 
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 14 matching lines @@
 
 class ExampleMenuModel : public ui::SimpleMenuModel,
                          public ui::SimpleMenuModel::Delegate {
  public:
   ExampleMenuModel();
 
   // ui::SimpleMenuModel::Delegate:
   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;
 
  private:
   enum GroupID {
     GROUP_MAKE_DECISION,
   };
 
   enum CommandID {
     COMMAND_DO_SOMETHING,
     COMMAND_SELECT_ASCII,
@@ skipping 68 matching lines @@
   return false;
 }
 
 bool ExampleMenuModel::IsCommandIdEnabled(int command_id) const {
   // All commands are enabled except for COMMAND_GO_HOME.
   return command_id != COMMAND_GO_HOME;
 }
 
 bool ExampleMenuModel::GetAcceleratorForCommandId(
     int command_id,
-    ui::Accelerator* accelerator) {
+    ui::Accelerator* accelerator) const {
   // We don't use this in the example.
   return false;
 }
 
 void ExampleMenuModel::ExecuteCommand(int command_id, int event_flags) {
   switch (command_id) {
     case COMMAND_DO_SOMETHING: {
       VLOG(0) << "Done something";
       break;
     }
@@ skipping 82 matching lines @@
 void MenuExample::CreateExampleView(View* container) {
   // We add a button to open a menu.
   ExampleMenuButton* menu_button = new ExampleMenuButton(
       ASCIIToUTF16("Open a menu"));
   container->SetLayoutManager(new FillLayout);
   container->AddChildView(menu_button);
 }
 
 }  // namespace examples
 }  // namespace views