Merge changes I37f0f315,I8cbf6044,Ibb598931,I5262bf11 into gingerbread

* changes:
  Fix a race that could cause GL commands to be executed from the wrong thread.
  RefBase subclasses can now decide how they want to be destroyed.
  Fix a race in SurfaceFlinger that could cause layers to be leaked forever.
  Fix a race-condtion in SurfaceFlinger that could lead to a crash.