GitLab

This was originally added by this CL:
https://chromiumcodereview.appspot.com/15714003

But later broke when the code was componentized here:
https://codereview.chromium.org/116863002

This CL restores the original functionality and adds
a test to hopefully prevent it from regressing in the
future.

BUG=460604

Review URL: https://codereview.chromium.org/942863003

Cr-Commit-Position: refs/heads/master@{#317655}