Prototype PerformanceEventTiming - https://bugzilla.mozilla.org/show_bug.cgi?id=1667836 - https://hg.mozilla.org/integration/autoland/rev/e86df3d99d16 - https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/40364#note_2729876 - Only true in Nightly - Does not clamp measurements