mash: Partially migrate ash/desktop_background to ash common types.

ash/desktop_background/desktop_background_widget_controller.cc

 // 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.
 
 #include "ash/desktop_background/desktop_background_widget_controller.h"
 
 #include "ash/ash_export.h"
 #include "ash/common/wm_lookup.h"
 #include "ash/common/wm_window.h"
 #include "ash/desktop_background/user_wallpaper_delegate.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_event_dispatcher.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/views/widget/widget.h"
-#include "ui/views/widget/widget_observer.h"
 
 namespace ash {
 namespace {
 
 class ShowWallpaperAnimationObserver : public ui::ImplicitAnimationObserver,
                                        public views::WidgetObserver {
  public:
   ShowWallpaperAnimationObserver(RootWindowController* root_window_controller,
                                  views::Widget* desktop_widget,
                                  bool is_initial_animation)
@@ skipping 124 matching lines @@
 }
 
 DesktopBackgroundWidgetController* AnimatingDesktopController::GetController(
     bool pass_ownership) {
   if (pass_ownership)
     return controller_.release();
   return controller_.get();
 }
 
 }  // namespace ash