Previously, we were reporting numbers that were far too low, because
we were getting way ahead of the GPU, and then spending all of our time
in finish (which isn't timed). That led to us picking very high loop
counts, so our wall clock time to run nanobench was very high, and our
reported times were very low. This fixes all of that, and removes all
the spam about not having fence support.
Change-Id: Ib9dfc043da82bf8ee6645b8627cfade66eb9864e
Reviewed-on: https://skia-review.googlesource.com/58001
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
