Use Ash's ShelfWindowWatcher for app panel windows.

ash/common/wm_window_property.h

 // Copyright 2016 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.
 
 #ifndef ASH_COMMON_WM_WINDOW_PROPERTY_H_
 #define ASH_COMMON_WM_WINDOW_PROPERTY_H_
 
 namespace ash {
 
 enum class WmWindowProperty {

[James Cook, 2016/11/02 17:53:44]

nit: Add a comment pointing readers to ui/aura/client/aura_constants.h for
detailed descriptions of the items. Or document more below.

[msw, 2016/11/10 21:07:46]

Done (in a prior CL).

   // Not a valid property; used for property key translation purposes.
   INVALID_PROPERTY,
 
   // Type bool.
   ALWAYS_ON_TOP,
 
+  // Type ImageSkia.
+  APP_ICON,
+
   // Type bool. See aura::client:kExcludeFromMruKey for details.
   EXCLUDE_FROM_MRU,
 
   // Type int, but cast to ui::ModalType.
   MODAL_TYPE,
 
   // Type int.
   SHELF_ICON_RESOURCE_ID,
 
   // Type int.
   SHELF_ID,
 
   // Type int, but cast to ShelfItemType.
   SHELF_ITEM_TYPE,
 
   // Type bool.
   SNAP_CHILDREN_TO_PIXEL_BOUNDARY,
 
   // Type SkColor. See aura::client::kTopViewColor for details.
   TOP_VIEW_COLOR,
 
   // Type int. See aura::client::kTopViewInset for details.
   TOP_VIEW_INSET,
+
+  // Type ImageSkia.
+  WINDOW_ICON,
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_WINDOW_PROPERTY_H_