GitLab

Add a pref that is default off to enable
safe search checking. There is no UI for this
yet.

BUG=1066643

Change-Id: I80fad2da4b3ab45790f94e5c7a5fb269815851f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134650
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Dominic Battré <battre@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759314}