[Bug 40828] Switching resolution in desktop mode makes task bar redraw on top of full screen game

https://bugs.winehq.org/show_bug.cgi?id=40828

--- Comment #23 from Olivier F. R. Dierick  ---
(In reply to Hamish Claxton from comment #12)
> Created attachment 63178 [details]
> systray: Hide systray for fullscreen games
>
> Completely rewritten, compares foreground window against desktop window.
> Handles borderless fullscreen modes.

Lines 788-790 are redundant with lines 939-941 in handle_systray(). That
function will be called when the desktop receives the WM_PARENTNOTIFY, so
sending the message is enough.