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

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 "ash/ash_export.h"
 #include "base/callback.h"
 #include "ui/aura/client/drag_drop_client.h"
@@ skipping 31 matching lines @@
       public aura::WindowObserver {
  public:
   DragDropController();
   virtual ~DragDropController();
 
   void set_should_block_during_drag_drop(bool should_block_during_drag_drop) {
     should_block_during_drag_drop_ = should_block_during_drag_drop;
   }
 
   // Overridden from aura::client::DragDropClient:
-  virtual int StartDragAndDrop(const ui::OSExchangeData& data,
-                               aura::RootWindow* root_window,
-                               const gfx::Point& root_location,
-                               int operation) OVERRIDE;
+  virtual int StartDragAndDrop(
+      const ui::OSExchangeData& data,
+      aura::RootWindow* root_window,
+      aura::Window* source_window,
+      const gfx::Point& root_location,
+      int operation,
+      ui::DragDropTypes::DragEventSource source) OVERRIDE;
   virtual void DragUpdate(aura::Window* target,
                           const ui::LocatedEvent& event) OVERRIDE;
   virtual void Drop(aura::Window* target,
                     const ui::LocatedEvent& event) OVERRIDE;
   virtual void DragCancel() OVERRIDE;
   virtual bool IsDragDropInProgress() OVERRIDE;
 
   // Overridden from aura::EventFilter:
   virtual bool PreHandleKeyEvent(aura::Window* target,
                                  ui::KeyEvent* event) OVERRIDE;
@@ skipping 39 matching lines @@
 
   scoped_ptr<ash::internal::DragDropTracker> drag_drop_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(DragDropController);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_DRAG_DROP_DRAG_DROP_CONTROLLER_H_