Continues to pass dEQP-GLES3.functional.ubo.*

Performance regression in draw call overhead is fixed.

BUG=angleproject:882
BUG=angleproject:1171

Change-Id: I1d827d70611c1bf743a7930796e31a54aca04b1e
Reviewed-on: https://chromium-review.googlesource.com/303473
Tryjob-Request: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>