has to be solved for animation anyway yes?

@rjkroege: We don't want to keep the cloned surface in sync with the original for the animation use-case. E.g. for maximize/restore we want the surface corresponding to the old bounds of the window to participate in the cross-fade. So what we want is more like a snapshot, and not a live copy.

Will be fixed/obsolete when we have the Surface Reference work completed.