Change Views menus to consistently use GetNativeTheme for theming.

ui/views/controls/menu/menu_item_view.cc

Index: ui/views/controls/menu/menu_item_view.cc
diff --git a/ui/views/controls/menu/menu_item_view.cc b/ui/views/controls/menu/menu_item_view.cc
index 36d6ab6c72a2d8ddc8e51ae52ed0aa94b6894af1..ff2737ea9a89771ed999dba162082f258d34fd55 100644
--- a/ui/views/controls/menu/menu_item_view.cc
+++ b/ui/views/controls/menu/menu_item_view.cc
@@ -568,10 +568,7 @@ void MenuItemView::SetMargins(int top_margin, int bottom_margin) {
 }
 
 const MenuConfig& MenuItemView::GetMenuConfig() const {
-  const MenuController* controller = GetMenuController();
-  if (controller)
-    return controller->menu_config_;
-  return MenuConfig::instance(NULL);
+  return MenuConfig::instance(GetNativeTheme());
 }
 
 MenuItemView::MenuItemView(MenuItemView* parent,