Code review comment for lp://qastaging/~afrantzis/mir/consume-only-not-rendered-buffers

I think this is a slightly awkward way to express what I proposed (without using time measurement):
https://code.launchpad.net/~vanvugt/mir/judder/+merge/216694

I'd prefer all future work avoided the unreliability of time measurement. Because with some careful planning you can avoid it.