/**
  * Background Update is controlled by the per-installation pref
  * "app.update.background.enabled". When Background Update was still in the
  * experimental phase, the default value of this pref may have been changed.
  * Now that the feature has been rolled out, we need to make sure that the
  * desired default value is restored.
  */
 async ensureExperimentToRolloutTransitionPerformed() {
   if (!lazy.UpdateUtils.PER_INSTALLATION_PREFS_SUPPORTED) {
     return;
   }
   const transitionPerformedPref = "app.update.background.rolledout";
   if (Services.prefs.getBoolPref(transitionPerformedPref, false)) {
     // writeUpdateConfigSetting serializes access to the config file. Because
     // of this, we can safely return here without worrying about another call
     // to this function that might still be in progress.
     return;
   }
   Services.prefs.setBoolPref(transitionPerformedPref, true);

Hi What is this "app.update.background.rolled out" setting? /** * Background Update is controlled by the per-installation pref * "app.update.background.enabled". When Background Update was still in the * experimental phase, the default value of this pref may have been changed. * Now that the feature has been rolled out, we need to make sure that the * desired default value is restored. */ async ensureExperimentToRolloutTransitionPerformed() { if (!lazy.UpdateUtils.PER_INSTALLATION_PREFS_SUPPORTED) { return; } const transitionPerformedPref = "'''app.update.background.rolledout'''"; if (Services.prefs.getBoolPref(transitionPerformedPref, false)) { // writeUpdateConfigSetting serializes access to the config file. Because // of this, we can safely return here without worrying about another call // to this function that might still be in progress. return; } Services.prefs.setBoolPref(transitionPerformedPref, true);