GitLab

This allows verifying that the keys provided via Web correspond to the
sync-ing user.

Bug: 1000146
Change-Id: Ib6eed0d244679703d55b164d2f71432b43695e43
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1847219Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703664}