| Index: ui/views/win/hwnd_message_handler_delegate.h | 
| diff --git a/ui/views/win/hwnd_message_handler_delegate.h b/ui/views/win/hwnd_message_handler_delegate.h | 
| index 87b9a96ef7aa968ce16b8845c650dd573c9d7c91..e17bf78eaa690a6a742035e5225542bc51248a1a 100644 | 
| --- a/ui/views/win/hwnd_message_handler_delegate.h | 
| +++ b/ui/views/win/hwnd_message_handler_delegate.h | 
| @@ -233,6 +233,9 @@ class VIEWS_EXPORT HWNDMessageHandlerDelegate { | 
| // handled by the delegate. | 
| virtual bool HandleScrollEvent(const ui::ScrollEvent& event) = 0; | 
|  | 
| +  // Called when the window size is about to change. | 
| +  virtual void HandleWindowSizeChanging() = 0; | 
| + | 
| protected: | 
| virtual ~HWNDMessageHandlerDelegate() {} | 
| }; | 
|  |