Since we're going to be calling meta_window_get_frame_rect in here
soon, I'd rather it be one method call, rather than two. We can't
put it at the toplevel, since that might cause infinite recursion
(e.g. meta_core_get calls meta_window_get_frame_rect calls
meta_ui_get_frame_borders calls meta_core_get, ...)
19d26dde92