GitLab

This took me a while to completely figure out, so I'm adding an overly
lengthy comment explaining how it works.

Bug: None
Change-Id: I73c511e690b044a938bb3bb0f154ad8982bcfd1c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1872424Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Commit-Queue: Lily Chen <chlily@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708607}