Converts ShellObserver from aura::Window to ash::WmWindow

ash/desktop_background/desktop_background_controller.h

 // Copyright (c) 2012 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_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_CONTROLLER_H_
 #define ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 79 matching lines @@
   bool MoveDesktopToLockedContainer();
 
   // Move all desktop widgets to unlocked container.
   // Returns true if the desktop moved.
   bool MoveDesktopToUnlockedContainer();
 
   // WindowTreeHostManager::Observer:
   void OnDisplayConfigurationChanged() override;
 
   // ShellObserver:
-  void OnRootWindowAdded(aura::Window* root_window) override;
+  void OnRootWindowAdded(WmWindow* root_window) override;
 
   // Returns the maximum size of all displays combined in native
   // resolutions.  Note that this isn't the bounds of the display who
   // has maximum resolutions. Instead, this returns the size of the
   // maximum width of all displays, and the maximum height of all displays.
   static gfx::Size GetMaxDisplaySizeInNative();
 
   // Returns true if the specified wallpaper is already stored
   // in |current_wallpaper_|.
   // If |compare_layouts| is false, layout is ignored.
@@ skipping 55 matching lines @@
   int wallpaper_reload_delay_;
 
   base::SequencedWorkerPool* blocking_pool_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopBackgroundController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_CONTROLLER_H_