Touch HUD app for mustash

ash/public/interfaces/container.mojom

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module ash.mojom;
 
 // Containers windows may be parented to.
 // NOTE: this is not the complete list of containers created by ash. See
 // ash/common/shell_window_ids.h for the complete this. This is only a subset
 // that other apps may need to parent windows to.
 enum Container {
   // TODO: remove everything but LOGIN_WINDOWS, http://crbug.com/616859.
   USER_BACKGROUND,
   USER_PRIVATE_SHELF,
   LOGIN_WINDOWS,
   // Status area widget and message center notification popups.
   STATUS,
   // Bubble windows, for example the sysui system tray bubble and the screen
   // brightness bubble.
   BUBBLES,
   MENUS,
   DRAG_AND_TOOLTIPS,
+  OVERLAY,
 };
 
 const string kWindowContainer_Property = "ash:window-container";