aura: Fix a couple of drag drop issues:

ui/aura/client/drag_drop_client.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 UI_AURA_CLIENT_DRAG_DROP_CLIENT_H_
 #define UI_AURA_CLIENT_DRAG_DROP_CLIENT_H_
 
 #include "ui/aura/aura_export.h"
 #include "ui/aura/event.h"
 
@@ skipping 22 matching lines @@
   virtual void DragUpdate(aura::Window* target, const LocatedEvent& event) = 0;
 
   // Called when mouse is released during a drag and drop.
   virtual void Drop(aura::Window* target, const LocatedEvent& event) = 0;
 
   // Called when a drag and drop session is cancelled.
   virtual void DragCancel() = 0;
 
   // Returns true if a drag and drop session is in progress.
   virtual bool IsDragDropInProgress() = 0;
+
+  // Returns the current cursor according to the appropriate drag effect. This
+  // should only be called if IsDragDropInProgress() returns true. If it is
+  // called otherwise, the returned cursor is arbitrary.
+  virtual gfx::NativeCursor GetDragCursor() = 0;
 };
 
 AURA_EXPORT void SetDragDropClient(RootWindow* root_window,
                                    DragDropClient* client);
 AURA_EXPORT DragDropClient* GetDragDropClient(RootWindow* root_window);
 
 }  // namespace client
 }  // namespace aura
 
 #endif  // UI_AURA_CLIENT_DRAG_DROP_CLIENT_H_