Gecko bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1371190

BUG=angleproject:2211

Change-Id: I10b866728a844668de6373c3a0968ea4e8256ff7
Reviewed-on: https://chromium-review.googlesource.com/747841Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>