Moves DragDropClient to aura/client

ui/aura/client/drag_drop_client.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 "ui/wm/public/drag_drop_client.h"
+#include "ui/aura/client/drag_drop_client.h"
 
 #include "ui/aura/window.h"
 #include "ui/aura/window_property.h"
 
 DECLARE_WINDOW_PROPERTY_TYPE(aura::client::DragDropClient*)
 
 namespace aura {
 namespace client {
 
 DEFINE_LOCAL_WINDOW_PROPERTY_KEY(
     DragDropClient*, kRootWindowDragDropClientKey, NULL);
 
 void SetDragDropClient(Window* root_window, DragDropClient* client) {
   DCHECK_EQ(root_window->GetRootWindow(), root_window);
   root_window->SetProperty(kRootWindowDragDropClientKey, client);
 }
 
 DragDropClient* GetDragDropClient(Window* root_window) {
   if (root_window)
     DCHECK_EQ(root_window->GetRootWindow(), root_window);
   return root_window ?
       root_window->GetProperty(kRootWindowDragDropClientKey) : NULL;
 }
 
 }  // namespace client
 }  // namespace aura