Gecko bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1325733

BUG=angleproject:2214

Change-Id: I6837a0fbf0bbbd0877f333f0625729445a5999aa
Reviewed-on: https://chromium-review.googlesource.com/748320Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>