This was broken sometime in the CollectVariables refactor.

BUG=angle:803

Change-Id: Iaa09449f02290c4547f87c1560465dc8998d957c
Reviewed-on: https://chromium-review.googlesource.com/224104Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>