title: requestStorageAccess Failure
body: <p>When I ask for storage access on a page in my iframe, It returns "Undefined".</p>
  
  <p>What does that signify?   I was hoping for a True, and would have understood false.  (it was denied) but what does Undefined mean in this context? What went wrong?</p>
  
  <pre><code>&lt;button id="start-button"&gt;Start Puctto&lt;/button&gt;
  
  &lt;script&gt;
  
  function gain_access() {
    document.cookie = "foo=bar";              // set a cookie
    document.hasStorageAccess().then(hasAccess =&gt; {
      if (!hasAccess) {     
        return document.requestStorageAccess();
      }
    }).then(_ =&gt; {   
      // Now we have first-party storage access!
      // Let's access some items from the first-party cookie jar
      document.cookie = "foo=bar";              // set a cookie
      localStorage.setItem("username", "John"); // access a localStorage entry
      window.opener.postMessage('set_session', '*');   
      window.location.href = document.referrer;
    }).catch(_ =&gt; {
      alert(_);
    });
  }
    document.getElementById('start-button').addEventListener('click', function (){
      console.log('Start button clicked');                
      gain_access();
  
    })
  &lt;/script&gt;
  </code></pre>