title: Desktop push notifications not displayed for chrome (macOs)
body: <p>I've integrated FCM based push notifications to my angular app, push notifications are getting triggered for ubuntu &amp; windows devices but fails to work on macOs. I am attaching the code of <strong>firebase-messaging-sw.js</strong> :</p>
  
  <pre><code>importScripts('https://www.gstatic.com/firebasejs/4.8.1/firebase-app.js');
  importScripts('https://www.gstatic.com/firebasejs/4.8.1/firebase-messaging.js');
  
  firebase.initializeApp({
      'messagingSenderId': SENDER_ID
  });
  
  self.addEventListener('fetch', event =&gt; {
      event.waitUntil(async function() {
          // Exit early if we don't have access to the client.
          // Eg, if it's cross-origin.
          if (!event.clientId) return;
  
          // Get the client.
          const client = await clients.get(event.clientId);
          // Exit early if we don't get the client.
          // Eg, if it closed.
          if (!client) return;
  
          // Send a message to the client.
          self.clients.matchAll().then(function(clients) {
              clients.forEach(function(client) {
                  client.postMessage({
                      msg: "Hey I just got a fetch from you!",
                      url: event.request.url
                  });
              });
          });
  
      }());
  })
  
  const messaging = firebase.messaging();
  
  messaging.setBackgroundMessageHandler(function(payload) {
      // Customize notification here
      const notificationTitle = 'Background Message Title';
      const notificationOptions = {
          body: 'Background Message body.',
          icon: '/firebase-logo.png'
      };
  
      return self.registration.showNotification(notificationTitle,
          notificationOptions);
  });
  </code></pre>
  
  <p>Do we have to add any extra configuration to add support for macOs Chrome?</p>