If not present, ASSERT error may happen in debug build.

BUG=chromium:643075

Change-Id: Ia57e3771ab4d2861aefc04287fbbce85232f1f4d
Reviewed-on: https://chromium-review.googlesource.com/381315
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>