BUG=angleproject:1416
TEST=conformance/extention/ in core profile
R=jmadill@chromium.org,geofflang@chromium.org,cwallez@chromium.org

Change-Id: I89b815929535586a2e90489129a1c6692bb87b3c
Reviewed-on: https://chromium-review.googlesource.com/353820
Tryjob-Request: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Zhenyao Mo <zmo@chromium.org>