perftests: Fix simple draw call benchmark. 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/265751 Reviewed-by: Brandon Jones <bajones@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>