title: Push Notification works Firefox but not work Chrome: Required member title is undefined
body: <p>I have a service worker running for push notifications. It register well but when i send a push notification works in firefox but not work in chrome (Version 74.0.3729.131 (Official Build) (64-bit)). Chrome worker recibe the push but can create the notification object.</p>
  
  <p>Chrome Error "worker.js:6 Uncaught (in promise) TypeError: Failed to execute 'showNotification' on 'ServiceWorkerRegistration': required member title is undefined.
      at worker.js:6"</p>
  
  <pre><code>self.addEventListener('push', ev =&gt; {
    const data = ev.data.json();
    self.registration.showNotification('Harcoded title', {
      actions: [{action: "get"}],
      body: data.body,
      title: 'Another hardcoded for testing',
      vibrate: [200, 100, 200, 100, 200, 100, 200],
      tag: 'SPI',
      icon: '/spi40/images/logo_spi.jpg'
    }).then(function(NotificationEvent) {console.log(NotificationEvent) });
    self.addEventListener('notificationclick', function(event) {
      event.notification.close();
      event.waitUntil(
          clients.openWindow('http://192.168.2.106/spi40/')
      );
    })
  });
  </code></pre>