R=titzer@chromium.org

Change-Id: I0be772d52b561e8664e128a9fb2c291256b2e9c2
Reviewed-on: https://chromium-review.googlesource.com/650287Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47817}