BUG=chromium:786021
R=titzer@chromium.org

Change-Id: I188ea4d639ef9d5ceeab5052e043ec1c9150bd77
Reviewed-on: https://chromium-review.googlesource.com/778282Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Brad Nelson <bradnelson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49506}