Still not hooked into telemetry, I talked with :janerik and :gfritzsche about
that, but test incoming!
This intentionally doesn't handle CSSOM and such for now, will file followups
for those, though should be trivial.
I want to unify / clean up how we do the use counters and the error reporting
stuff for CSSOM, since the current function call still shows up in profiles,
but that should be a follow-up.
Differential Revision: https://phabricator.services.mozilla.com/D3828