Carlos Garnacho authored Nov 30, 2018 and Jonas Ådahl committed Dec 01, 2018

It is meant to hold surfaces that require a ClutterActor, just like wl/xdg
shell surfaces and subsurfaces. Make it inherit from MetaWaylandActorSurface
so it gets that for free.

The type declaration is also made completely private, in order to avoid
cyclic dependency between meta-wayland-surface.h and
meta-wayland-actor-surface.h. We just require the GType fro assign_role()
anyway.