R=titzer@chromium.org

Change-Id: Ie65c03347b0619a107bc06725ce587e0270fa9a1
Reviewed-on: https://chromium-review.googlesource.com/707102
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48425}