internal override void ScrollWindow(IntPtr handle, Rectangle area, int XAmount, int YAmount, bool clear) {
/*
* This used to use a HIViewScrollRect but this causes issues with the fact that we dont coalesce
* updates properly with our short-circuiting of the window manager. For now we'll do a less
* efficient invalidation of the entire handle which appears to fix the problem
* see bug #381084
*/
Hwnd hwnd = Hwnd.ObjectFromHandle (handle);
Invalidate (handle, new Rectangle (0, 0, hwnd.Width, hwnd.Height), false);
}