Code review comment for lp:~vanvugt/mir/fix-1665802

I'm hesitant to endorse this still, because it reduces our ability to catch up in almost-full-framerate scenarios across the board (instead opting to sleep and hope that's enough to give the server more GPU time). I feel this is something we shouldn't be "fixing" because it's not a Mir bug and more important devices (like everything other than Freedreno) could suffer slightly if we land this.

I'll look at other workarounds still that don't make the same sacrifice (although may be much less clean in code than this).