Replace ButtonDropDown menu implementation (Menu2) with MenuItemView.

views/controls/menu/menu_model_adapter.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 VIEWS_CONTROLS_MENU_MENU_MODEL_ADAPTER_H_
 #define VIEWS_CONTROLS_MENU_MENU_MODEL_ADAPTER_H_
 #pragma once
 
 #include <map>
 
@@ skipping 25 matching lines @@
   virtual void ExecuteCommand(int id) OVERRIDE;
   virtual void ExecuteCommand(int id, int mouse_event_flags) OVERRIDE;
   virtual bool GetAccelerator(int id,
                               views::Accelerator* accelerator) OVERRIDE;
   virtual std::wstring GetLabel(int id) const OVERRIDE;
   virtual const gfx::Font& GetLabelFont(int id) const OVERRIDE;
   virtual bool IsCommandEnabled(int id) const OVERRIDE;
   virtual bool IsItemChecked(int id) const OVERRIDE;
   virtual void SelectionChanged(MenuItemView* menu) OVERRIDE;
   virtual void WillShowMenu(MenuItemView* menu) OVERRIDE;
+  virtual void WillHideMenu(MenuItemView* menu) OVERRIDE;
 
  private:
   // Implementation of BuildMenu().  index_offset is both input and output;
   // on input it contains the offset from index to command id for the model,
   // and on output it contains the offset for the next model.
   void BuildMenuImpl(MenuItemView* menu, ui::MenuModel* model);
 
   // Container of ui::MenuModel pointers as encountered by preorder
   // traversal.  The first element is always the top-level model
   // passed to the constructor.
   ui::MenuModel* menu_model_;
 
   // Map MenuItems to MenuModels.  Used to implement WillShowMenu().
   std::map<MenuItemView*, ui::MenuModel*> menu_map_;
 
   DISALLOW_COPY_AND_ASSIGN(MenuModelAdapter);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_MENU_MENU_MODEL_ADAPTER_H_