a3aa6c9aa9
First, the window manager tells us when a surface is no longer needed. At this point, several things happen: - the surface is removed from the active/visible list - it is added to a purgatory list, where it waits for all clients to release their reference - it destroys all data/state that can be spared Later, when all clients are done, the remains of the Surface are disposed off: it is removed from the purgatory and destroyed. In particular its gralloc buffers are destroyed at that point (when we're sure nobody is using them anymore).