Code review comment for lp:~alan-griffiths/miral/tidy-SurfaceObserver-part1

In qtmir, SurfaceObserver::notifySurfaceModifications is called by src/platforms/mirserver/mirwindowmanager.cpp

There's no mirwindowmanager.cpp in miral-qt anymore, so this code is already broken here.

Question now is when did it get removed and what replaces it.