Bug: 
Change-Id: I957e96129d9194eaae406383454f7cd09f53c97f
Reviewed-on: https://chromium-review.googlesource.com/753514Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49145}