mash: Prerequisites for removing ShelfDelegate.

ash/shelf/wm_shelf.cc

 // 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.
 
 #include "ash/shelf/wm_shelf.h"
 
 #include "ash/public/cpp/config.h"
 #include "ash/public/cpp/shelf_item_delegate.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_bezel_event_handler.h"
 #include "ash/shelf/shelf_controller.h"
-#include "ash/shelf/shelf_delegate.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_locking_manager.h"
 #include "ash/shelf/shelf_model.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shelf/wm_shelf_observer.h"
 #include "ash/shell.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/wm_window.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 351 matching lines @@
 
 void WmShelf::OnBackgroundUpdated(ShelfBackgroundType background_type,
                                   AnimationChangeType change_type) {
   if (background_type == GetBackgroundType())
     return;
   for (auto& observer : observers_)
     observer.OnBackgroundTypeChanged(background_type, change_type);
 }
 
 }  // namespace ash