message: Catch errors unregistering service workers
diff: @@ -266,7 +266,10 @@ if ('serviceWorker' in navigator) {
  .then(() => new Promise(r => navigator.serviceWorker.controller ? r() : navigator.serviceWorker.addEventListener('controllerchange', () => r())))
  .then(() => navigator.serviceWorker.controller.postMessage({topic: 'setFactor', value: window.SERVER_FLAGS.loadTestFactor}));
  } else {
  - navigator.serviceWorker.getRegistrations().then((registrations) => registrations.forEach(reg => reg.unregister()));
  + navigator.serviceWorker.getRegistrations()
  + .then((registrations) => registrations.forEach(reg => reg.unregister()))
  + // eslint-disable-next-line no-console
  + .catch(e => console.warn('Error unregistering service workers', e));
  }
  }
  