make menus, bubbles, etc. top level windows on aura

ui/views/widget/desktop_aura/desktop_native_widget_aura.h

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.h
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
index f358b588534cb3ccd28836e150e45098e38210de..529a732bde2b30bf5c57dfd9737fec647c4b1ef3 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
@@ -28,6 +28,7 @@ class CompoundEventFilter;
 class InputMethodEventFilter;
 class ShadowController;
 class TooltipController;
+class VisibilityController;
 }
 
 class DesktopRootWindowHost;
@@ -228,6 +229,8 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
   scoped_ptr<corewm::TooltipController> tooltip_controller_;
   scoped_ptr<TooltipManagerAura> tooltip_manager_;
 
+  scoped_ptr<views::corewm::VisibilityController> visibility_controller_;
+
   // See comments in OnLostActive().
   bool restore_focus_on_activate_;