title: Event listener for window.fetch
body: <p>Is there a way to globally monitor all <code>window.fetch</code> requests? I know it works with Promises, but I need to get notified whenever any of such requests is done (fail/success) and I have no access to the functions which invoke these or which are success/fail handlers.</p>
  <p>So basically I'm looking for something like:</p>
  <pre><code>window.addEventListener('fetch', ev =&gt; {
    if (ev.type == 'FetchSuccess') {
      // process ev.response
    }
  });
  </code></pre>