Bug #7221449 SurfaceTexture already deletes the GL texture when detachFromContext is invoked. The newly introduced refcount would casue the Layer object to be destroyed later and attempt to delete the GL texture again. By the time the second cleanup occurs, the texture name might have been reused by somebody else, resulting in erroneous behaviors. Change-Id: I257c589fea64b34c00f46fbfaa7732e6854a5e41