(Minimal change to support easy backmerging.)

BUG=v8:5938

Change-Id: Icad35c90d9c2451cd63a4ab7e495d9b5252da693
Reviewed-on: https://chromium-review.googlesource.com/439170Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43031}