Replace ButtonDropDown menu implementation (Menu2) with MenuItemView.

views/controls/button/button_dropdown.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_BUTTON_BUTTON_DROPDOWN_H_
 #define VIEWS_CONTROLS_BUTTON_BUTTON_DROPDOWN_H_
 #pragma once
 
 #include "base/task.h"
 #include "views/controls/button/image_button.h"
-#include "views/controls/menu/menu_2.h"
+
+namespace ui {
+class MenuModel;
+}  // namespace ui
 
 namespace views {
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // ButtonDropDown
 //
 // A button class that when pressed (and held) or pressed (and drag down) will
 // display a menu
 //
@@ skipping 22 matching lines @@
   // implementation, both left and right mouse buttons can trigger a change
   // to the PUSHED state.
   virtual bool ShouldEnterPushedState(const MouseEvent& event) OVERRIDE;
 
  private:
   // Internal function to show the dropdown menu
   void ShowDropDownMenu(gfx::NativeView window);
 
   // The model that populates the attached menu.
   ui::MenuModel* model_;
-  scoped_ptr<Menu2> menu_;
 
   // Y position of mouse when left mouse button is pressed
   int y_position_on_lbuttondown_;
 
   // A factory for tasks that show the dropdown context menu for the button.
   ScopedRunnableMethodFactory<ButtonDropDown> show_menu_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ButtonDropDown);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_BUTTON_BUTTON_DROPDOWN_H_