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

-void SurfaceObserver::notifySurfaceModifications(const mir::shell::SurfaceSpecification &modifications)
I'm only happy to proceed with this removal when we have the miral-based equivalent to this ready to land. Otherwise it will upset Daniels work integrating miral-qt with unity8.