The mInFlightCommand vector could grow faster than
the GPU can complete tasks. Check for this edge case
and give the GPU a chance to catch up with work.

Also allows us to enable performance tests for Draw
Calls on vulkan since it was affected by this limit
check before.

Bug: angleproject:2742
Change-Id: I66a86ea6b5300fa3d74b07dc341aa597824b5f09
Reviewed-on: https://chromium-review.googlesource.com/1147607Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>