fixup! BB 45120: Add tests for Base Browser

        if getattr(self, "testRootAbs", None):

            prefs["mochitest.testRoot"] = self.testRootAbs

        # 001-base-profile.js forces HTTPS-Only mode on, which upgrades

        # requests to the (plain http) mochitest web server and breaks test

        # content loading. Unlike a real Tor Browser install, that hardening

        # has nothing to do with what these tests exercise, and it applies

        # regardless of whether --tor-bootstrap is used.

        prefs["dom.security.https_only_mode"] = False

        prefs["dom.security.https_only_mode_pbm"] = False

        # 001-base-profile.js sets security.nocertdb, so NSS never loads the

        # on-disk cert DB that fillCertificateDB() populates with mochitest's

        # test CA, and any HTTPS test content would fail with an

        # untrusted-issuer error. Persisting a cert DB is exactly what

        # nocertdb exists to prevent in a real Tor Browser profile for

        # privacy, but that doesn't apply here: this profile is thrown away

        # after the run, so there's nothing to leak.

        prefs["security.nocertdb"] = False

        # See if we should use fake media devices.

        if options.useTestMediaDevices:

            prefs["media.audio_loopback_dev"] = self.mediaDevices["audio"]["name"]