Get drag and drop working for win aura.

ui/views/widget/drop_target_win.h

 // Copyright (c) 2011 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_VIEWS_WIDGET_DROP_TARGET_WIN_H_
 #define UI_VIEWS_WIDGET_DROP_TARGET_WIN_H_
 
 #include "ui/base/dragdrop/drop_target.h"
 #include "ui/views/widget/drop_helper.h"
 
 namespace views {
 
 class View;
 namespace internal {
 class RootView;
 }
 
 // DropTargetWin takes care of managing drag and drop for NativeWidgetWin. It
 // converts Windows OLE drop messages into Views drop messages.
 //
 // DropTargetWin uses DropHelper to manage the appropriate view to target
 // drop messages at.
 class DropTargetWin : public ui::DropTarget {
  public:
-  explicit DropTargetWin(internal::RootView* root_view);
+  DropTargetWin(internal::RootView* root_view, HWND drop_target);
   virtual ~DropTargetWin();
 
   // If a drag and drop is underway and view is the current drop target, the
   // drop target is set to null.
   // This is invoked when a View is removed from the RootView to make sure
   // we don't target a view that was removed during dnd.
   void ResetTargetViewIfEquals(View* view);
 
  protected:
   virtual DWORD OnDragOver(IDataObject* data_object,
@@ skipping 10 matching lines @@
 
  private:
   views::DropHelper helper_;
 
   DISALLOW_COPY_AND_ASSIGN(DropTargetWin);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DROP_TARGET_WIN_H_