Bug: 15185239
Bug: 15238382
Make DeferredLayerUpdater ref counted so that
HardwareLayer:finalizer() works non-crashily on
leaked layers
Give DeferredLayerUpdater the ability to have a layer destroyer
set so that leaked layers can still be recycled on the
RenderThread
Order layer updates based off of pushLayerUpdate() calls to fix
issue with nested layers
Change-Id: I4449cee607f7e5126e02fed7464cf48038e3dfdf