R=clemensh@chromium.org

Bug: 
Change-Id: I54e4d02cd5665d3ba3fd2e91da05599a915c0317
Reviewed-on: https://chromium-review.googlesource.com/712654Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48457}