Similar to prior fix for GLES2, validation now correctly returns INVALID_ENUM instead of shorting out. BUG=angleproject:1168 Change-Id: I8247b0b3520b0f116856049c85606bb44fa24021 Reviewed-on: https://chromium-review.googlesource.com/303472Reviewed-by: Jamie Madill <jmadill@chromium.org> Tryjob-Request: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Tommy Martino <tmartino@chromium.org>
