Moves DragDropClient to aura/client

ash/drag_drop/drag_drop_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_DRAG_DROP_DRAG_DROP_CONTROLLER_H_
 #define ASH_DRAG_DROP_DRAG_DROP_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/common/wm_display_observer.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/dragdrop/os_exchange_data.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/event_handler.h"
 #include "ui/gfx/animation/animation_delegate.h"
 #include "ui/gfx/geometry/rect.h"
-#include "ui/wm/public/drag_drop_client.h"
 
 namespace gfx {
 class LinearAnimation;
 }
 
 namespace ash {
 class DragDropTracker;
 class DragDropTrackerDelegate;
 class DragImageView;
 
@@ skipping 101 matching lines @@
   std::unique_ptr<ui::GestureEvent> pending_long_tap_;
 
   base::WeakPtrFactory<DragDropController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DragDropController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DRAG_DROP_DRAG_DROP_CONTROLLER_H_