Code review comment for lp:~vanvugt/mir/unfreeze-1

Can confirm the visual improvement and the code seems sensible.

A couple of questions/concerns about the overallocation behavior:

135 + * 5. Overallocate; more buffers! Yes, see below.
136 + */
137 + auto const& buffer = gralloc->alloc_buffer(the_properties);

1. In framedropping mode, could we end up allocating more buffers than needed (e.g. because of some kind of spike) which we will then not release?

2. In framedropping mode, could we end up in a situation in which we continuously allocate buffers, eventually exhausting graphics memory? Could a malicious client force such behavior?