Make the cancelling of drag and drop match Safari for Windows.

chrome/browser/renderer_host/render_view_host.h

 // Copyright (c) 2009 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 CHROME_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_H_
 #define CHROME_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 273 matching lines @@
   // destroyed.
   void JavaScriptMessageBoxWindowDestroyed();
 
   // Notifies the RenderView that the modal html dialog has been closed.
   void ModalHTMLDialogClosed(IPC::Message* reply_msg,
                              const std::string& json_retval);
 
   // Copies the image at the specified point.
   void CopyImageAt(int x, int y);
 
+  // Notifies the renderer that a drag and drop was cancelled. This is
+  // necessary because the render may be the one that started the drag.
+  void DragSourceCancelledAt(
+      int client_x, int client_y, int screen_x, int screen_y);
+
   // Notifies the renderer that a drop occurred. This is necessary because the
   // render may be the one that started the drag.
   void DragSourceEndedAt(
       int client_x, int client_y, int screen_x, int screen_y);
 
   // Notifies the renderer that a drag and drop operation is in progress, with
   // droppable items positioned over the renderer's view.
   void DragSourceMovedTo(
       int client_x, int client_y, int screen_x, int screen_y);
 
@@ skipping 295 matching lines @@
 
   // True if the render view can be shut down suddenly.
   bool sudden_termination_allowed_;
 
   NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHost);
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_H_