title: Ping service worker without displaying a notification
body: <p>I’m trying to monitor which service workers are active (ie, which users have their browsers open). I came up with a solution that sends a simple ping through the web push API, and that would trigger the service worker to send a ping request to my server. But I’m finding that if I don’t display a notification to the user, I get an alert from Chrome. </p>
  
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  <p>Am I doing something wrong, or is there another way to solve this problem?</p>