no change of functionality -- the old behavior is implemented
on top of this new protocol.
this new protocol will allow, eventually, to pass informations
about displays and layer stacks.
Change-Id: Ic6c2295e61ec8ecbc8ce01ab7664e35d928202fc
This change adds a crop rectangle specified in window coordinates to the layer
state. The all window pixels outside this crop rectangle are treated as though
they were fully transparent. This change also adds the plumbing necessary for
WindowManager to set that crop.
Change-Id: I582bc445dc8c97d4c943d4db8d582a6ef5a66081