We have support for primitive restart in the GL renderer, but we
didn't complete support for the state query.

BUG=angleproject:1101

Change-Id: I4c6ad10642f7de1d09718c4582f1037782cced58
Reviewed-on: https://chromium-review.googlesource.com/309151
Tryjob-Request: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@google.com>
Tested-by: Jamie Madill <jmadill@chromium.org>