[sergeykish]

Essentially it is

    performance.getEntriesByType("navigation")[0].nextHopProtocol

and background task to update UI, plus a link to chrome://net-export/

This one is not hard to audit but in current model should be done by each user.

[anon84598]

If that's it, you could just save it as a bookmark:

    javascript:alert(performance.getEntriesByType("navigation")[0].nextHopProtocol)

[voltagex_]

That works in Firefox, too.