Use a ui::MenuModel in views::Combobox

ui/views/controls/menu/menu_config.h

 // 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.
 
 #ifndef UI_VIEWS_CONTROLS_MENU_MENU_CONFIG_H_
 #define UI_VIEWS_CONTROLS_MENU_MENU_CONFIG_H_
 
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/font_list.h"
 #include "ui/views/views_export.h"
@@ skipping 95 matching lines @@
 
   // True if the context menu's should be offset from the cursor position.
   bool offset_context_menus;
 
   // True if the scroll container should add a border stroke around the menu.
   bool use_outer_border;
 
   // True if the icon is part of the label rather than in its own column.
   bool icons_in_label;
 
+  // True if a combobox menu should put a checkmark next to the selected item.
+  bool check_selected_combobox_item;
+
   const ui::NativeTheme* native_theme;
 
   // Delay, in ms, between when menus are selected or moused over and the menu
   // appears.
   int show_delay;
 
   // Radius of the rounded corners of the menu border. Must be >= 0.
   int corner_radius;
 
  private:
   // Configures a MenuConfig as appropriate for the current platform.
   void Init(const ui::NativeTheme* theme);
 
   // TODO: temporary until we standardize.
   void InitAura(const ui::NativeTheme* theme);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_MENU_CONFIG_H_