Comment 9 for bug 1418081

Ignoring the fact that I feel the back-and-forth of occlusion flagging feels like a kludge, I think I could "fix" this easily.

But I would much rather we treated compositing as a one-way activity where the scene (model) is viewed by the compositor (view). Allowing the compositor to touch the scene with occluded() as it does is a bit messy.