Code review comment for lp:~vanvugt/mir/fix-1420678

Hm. This doesn't look incorrect, but it also looks like it's papering over a problem elsewhere.

I *think* this might be an artefact of an incorrect fix for bug #1319765? The problem identified there being that there's no additional composition scheduled when the client has submitted a frame and is blocking for its next buffer. This was solved by fake-consuming the client frame; it would seem to be more correct to ensure that the frame that the client has already submitted appropriately triggers composition?