This was accidentally left out of commit
547cbd46
"Validate uniform binding at link time".

BUG=angleproject:1893

Change-Id: I945608fd9aef8a605d69f1109ead2460aab0c228
Reviewed-on: https://chromium-review.googlesource.com/448456Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>