GitLab

This allows us to stop depending on the impl in browser_prefs.cc.
Fixes `gn check` errors. Split out from crrev.com/c/2383400

Bug: 898837
Change-Id: I777200b6a49710e1496fb3189f8bbed80fb3cbb3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2386437
Auto-Submit: Glen Robertson <glenrob@chromium.org>
Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803925}