mash: Use ash shell window container ids instead of ash::mojom::Container

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.
-  WALLPAPER,
-  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";