Previously the code was only testing the validation logic. Fix this
by testing validation-only and a simple single quad draw benchmark.

BUG=468852

Change-Id: I510deea08fee5932f51ea39883ed91652be476df
Reviewed-on: https://chromium-review.googlesource.com/265751Reviewed-by: Brandon Jones <bajones@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>