aura: Remove layerless windows.

ui/views/widget/native_widget_mac_unittest.mm

Index: ui/views/widget/native_widget_mac_unittest.mm
diff --git a/ui/views/widget/native_widget_mac_unittest.mm b/ui/views/widget/native_widget_mac_unittest.mm
index af715a15d7deeff67abb15607e163927b1d9cea7..ccc1e4c48c56de2886e7939469c70ea04e32ed59 100644
--- a/ui/views/widget/native_widget_mac_unittest.mm
+++ b/ui/views/widget/native_widget_mac_unittest.mm
@@ -163,8 +163,9 @@ class PaintCountView : public View {
 TEST_F(NativeWidgetMacTest, MiniaturizeExternally) {
   Widget* widget = new Widget;
   Widget::InitParams init_params(Widget::InitParams::TYPE_WINDOW);
-  // Don't add a layer, so that calls to paint can be observed synchronously.
-  init_params.layer_type = aura::WINDOW_LAYER_NONE;
+  // Make the layer not drawn, so that calls to paint can be observed
+  // synchronously.
+  init_params.layer_type = ui::LAYER_NOT_DRAWN;
   widget->Init(init_params);
 
   PaintCountView* view = new PaintCountView();