Use a ui::MenuModel in views::Combobox

ui/views/controls/menu/menu_config.h

Index: ui/views/controls/menu/menu_config.h
diff --git a/ui/views/controls/menu/menu_config.h b/ui/views/controls/menu/menu_config.h
index e697d208bd79cc30cfb8ca834e1019bf0ae5eaa9..936f80f0e6e65ceab90ff101c1d32067143aa9d8 100644
--- a/ui/views/controls/menu/menu_config.h
+++ b/ui/views/controls/menu/menu_config.h
@@ -113,6 +113,9 @@ struct VIEWS_EXPORT MenuConfig {
   // 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