SimpleMenuModel and ButtonMenuItemModel implement AcceleratorProvider.

ui/base/models/button_menu_item_model.h

 // Copyright (c) 2011 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 UI_BASE_MODELS_BUTTON_MENU_ITEM_MODEL_H_
 #define UI_BASE_MODELS_BUTTON_MENU_ITEM_MODEL_H_
 
 #include <vector>
 
+#include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
+#include "ui/base/accelerators/accelerator.h"
 #include "ui/base/ui_base_export.h"
 
 namespace ui {
 
-class Accelerator;
-
 // A model representing the rows of buttons that should be inserted in a button
 // containing menu item.
 class UI_BASE_EXPORT ButtonMenuItemModel {
  public:
   // Types of buttons.
   enum ButtonType {
     TYPE_SPACE,
     TYPE_BUTTON,
     TYPE_BUTTON_LABEL
   };
 
-  class UI_BASE_EXPORT Delegate {
+  class UI_BASE_EXPORT Delegate
+      : NON_EXPORTED_BASE(public AcceleratorProvider) {
    public:
     // Some command ids have labels that change over time.
     virtual bool IsItemForCommandIdDynamic(int command_id) const;
     virtual base::string16 GetLabelForCommandId(int command_id) const;
 
     // Performs the action associated with the specified command id.
     virtual void ExecuteCommand(int command_id, int event_flags) = 0;
     virtual bool IsCommandIdEnabled(int command_id) const;
     virtual bool DoesCommandIdDismissMenu(int command_id) const;
 
-    // Gets the accelerator for the specified command id. Returns true if the
-    // command id has a valid accelerator, false otherwise. By default, returns
-    // false for all commands.
-    virtual bool GetAcceleratorForCommandId(int command_id,
-                                            ui::Accelerator* accelerator) const;
+    // AcceleratorProvider overrides:
+    // By default, returns false for all commands. Can be further overridden.
+    bool GetAcceleratorForCommandId(
+        int command_id,
+        ui::Accelerator* accelerator) const override;
 
    protected:
-    virtual ~Delegate() {}
+    ~Delegate() override {}
   };
 
   ButtonMenuItemModel(int string_id, ButtonMenuItemModel::Delegate* delegate);
   ~ButtonMenuItemModel();
 
   // Adds a button that will emit |command_id|. All buttons created through
   // this method will have the same size, based on the largest button.
   void AddGroupItemWithStringId(int command_id, int string_id);
 
   // Adds a button that has an icon instead of a label.
@@ skipping 59 matching lines @@
   std::vector<Item> items_;
 
   Delegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(ButtonMenuItemModel);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_MODELS_BUTTON_MENU_ITEM_MODEL_H_