Clarify geometry management for SurfaceView

In the hardware accelerated case, RenderThread needs
to be the authority of information on the geometry of
the SurfaceView (this will occur via moving the
repositionWindow call to RenderThread). In order
to support this we have to enable calling relayoutWindow
without geometry (so that it will not fight with
repositionWindow). Add such a mode to relayoutWindow
and use it from SurfaceView. Add size to repositionChild
while we are here.

Change-Id: I12f85f586a38bf86367f3d964cb49f19003d441f