They probably don’t.

If you’re talking about when they’re in the office and on the job, chances are they’re not using Chrome at all, they’re using IE or Edge (depending on the Windows version deployed these days), with group policy pushed out from the domain that prevents installing any additional software (note: this doesn’t prevent the use of portable installs of software, uncompressed to their Documents/ subdirectory or something) (but most of those folks don’t know anything about portable software).

There is also a very good chance that they’re still blocking Youtube on NIPR for bandwidth management purposes.

I’ve no idea if US .govs are using Google Orgs for anything these days. When I was still a Beltway Bandit it was all Exchange with Outlook, all the time.