This simple perf test already in the source does a great job at this.

Bug: angleproject:2389
Change-Id: I94ff14e0eab1cb49a8d19725056ad8f7f008ac05
Reviewed-on: https://chromium-review.googlesource.com/962962Reviewed-by: Frank Henigman <fjhenigman@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>