If we return a direct ref that is not possible, since we own a ref to it.
This is problematic as the gdkwindow.c code uses destruction to track
outstanding surfaces.
We fix this by returning a subsurface.
This just runs:
for i in *.[ch]; do
sed -i s/DisplayX11/DisplayBroadway/g $i;
sed -i s/PrivateX11/PrivateBroadway/g $i;
sed -i s/ImplX11/ImplBroadway/g $i;
sed -i s/KeymapX11/KeymapBroadway/g $i;
sed -i s/ScreenX11/ScreenBroadway/g $i;
sed -i s/GdkX11Monitor/GdkBroadwayMonitor/g $i;
sed -i s/_X11/_BROADWAY/g $i;
sed -i s/x11/broadway/g $i;
done
