CcRRLabeler assumes an X11 session using override redirect toplevel
windows which are positioned in global desktop coordinates. Since this
isn't available on Wayland sessions, we're moving to a DBus API which
gnome-shell implements and works the same on both X11 an Wayland
sessions.
As side-effects, we get native looking gnome-shell OSD labels without
having to mimic the style ourselves and we're also now able to easily
show labels on mirrored setups.
https://bugzilla.gnome.org/show_bug.cgi?id=743743
c6970ec8eb