1367366 - Implement "stable" clock based on Kinto clock skew

Status: NEW

(Toolkit :: Telemetry, enhancement, P3)

Description

[Georg Fritzsche [:gfritzsche]]

Through Kinto we get clock skew numbers that are a in the precision range of "a few hours".
This is already used in production for the bad clock warnings for certificates.

See "services.blocklist.clock_skew_seconds":
https://dxr.mozilla.org/mozilla-central/search?q=blocklist+clock_skew_seconds&redirect=true

We should be able to build a "good enough" stable clock on this for the purposes of probe expiry by date.

See bug 1334515, comment 2 ff. for the details.