BUG=v8:6291, v8:811
R=marja@chromium.org, vogelheim@chromium.org

Change-Id: I978ea446d7b42092592b0a3ae3c99626e36d40fd
Reviewed-on: https://chromium-review.googlesource.com/485099
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Daniel Vogelheim <vogelheim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44819}