GitLab

Based on https://codereview.chromium.org/2044223004 by littledan@chromium.org

BUG=v8:4483, 621515
R=littledan@chromium.org, yangguo@chromium.org, dgozman@chromium.org, pfeldman@chromium.org

Review-Url: https://codereview.chromium.org/2071483002
Cr-Commit-Position: refs/heads/master@{#400718}