aura: Add flag to indicate if a drag session is started with touch or mouse.

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/base/dragdrop/drag_drop_types.h"
 #include "ui/gfx/native_widget_types.h"
 
 namespace gfx {
 class Point;
 }
 
 namespace ui {
 class LocatedEvent;
 class OSExchangeData;
 }
 
 namespace aura {
 class RootWindow;
 class Window;
 namespace client {
 
 // An interface implemented by an object that controls a drag and drop session.
 class AURA_EXPORT DragDropClient {
  public:
   virtual ~DragDropClient() {}
 
   // Initiates a drag and drop session. Returns the drag operation that was
   // applied at the end of the drag drop session. |root_location| is in the
   // RootWindow's coordinate system.
   virtual int StartDragAndDrop(const ui::OSExchangeData& data,
                                aura::RootWindow* root_window,
                                const gfx::Point& root_location,
-                               int operation) = 0;
+                               int operation,
+                               ui::DragDropTypes::DragEventSource source) = 0;
 
   // Called when mouse is dragged during a drag and drop.
   virtual void DragUpdate(aura::Window* target,
                           const ui::LocatedEvent& event) = 0;
 
   // Called when mouse is released during a drag and drop.
   virtual void Drop(aura::Window* target,
                     const ui::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;
 };
 
 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_