R=titzer@chromium.org, mstarzinger@chromium.org, joransiu@ca.ibm.com, jbarboza@ca.ibm.com

Bug: 
Change-Id: Ie7424ed26464574470ce5ae4184092cf46920da9
Reviewed-on: https://chromium-review.googlesource.com/867550Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#50628}