R=cbruni@chromium.org

Bug: 
Change-Id: Id1993e64375084e43479c20607a5c20778117ecc
Reviewed-on: https://chromium-review.googlesource.com/601910Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47215}