How to listen for web notification permission change
<p>According to the <a href="https://developer.mozilla.org/en-US/docs/Web/API/Notification/permission" rel="noreferrer">Notification.permission</a> spec from MDN, we can check the current user permission for web notification. </p>

<p>However, is there any way to listen for this permission change? Something like this?</p>

<pre><code>.on(Notification.permission, 'changed', function(){ }
</code></pre>