BUG=chromium:863205
R=clemensh@chromium.org

Change-Id: I15f3a09e15210a80b155def5761d9aead95d19b7
Reviewed-on: https://chromium-review.googlesource.com/1156386Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54811}