wrench_menu: use NativeTheme colors under aura

ui/views/controls/menu/menu_config_views.cc

Index: ui/views/controls/menu/menu_config_views.cc
diff --git a/ui/views/controls/menu/menu_config_views.cc b/ui/views/controls/menu/menu_config_views.cc
index 7cbc23596c67400db2ac1939d6f3881646f4e16a..e07c8a3fcaf74b982e3954a64c1be3bc8ad56f88 100644
--- a/ui/views/controls/menu/menu_config_views.cc
+++ b/ui/views/controls/menu/menu_config_views.cc
@@ -24,12 +24,11 @@ static const int kMenuCornerRadiusForAura = 2;
 
 #if !defined(OS_WIN)
 void MenuConfig::Init(const ui::NativeTheme* theme) {
-  InitAura();
+  InitAura(theme);
 }
 #endif
 
-void MenuConfig::InitAura() {
-  ui::NativeTheme* theme = ui::NativeThemeAura::instance();
+void MenuConfig::InitAura(const ui::NativeTheme* theme) {
   text_color = theme->GetSystemColor(
       ui::NativeTheme::kColorId_EnabledMenuItemForegroundColor);
   menu_horizontal_border_size = 0;
@@ -64,7 +63,8 @@ void MenuConfig::InitAura() {
 const MenuConfig& MenuConfig::instance(const ui::NativeTheme* theme) {
   static MenuConfig* views_instance = NULL;
   if (!views_instance)
-    views_instance = new MenuConfig(ui::NativeTheme::instance());
+    views_instance = new MenuConfig(theme ?
+        theme : ui::NativeTheme::instance());
   return *views_instance;
 }
 #endif