title: Chrome extension desktop notification show 2 time
body: <p>I'm create a chrome extension with desktop notification, everything is fine but for each record 2 notification shows I used tag for prvent the issue popup shows on notification but my music function play twice.</p>
  
  <pre><code>function sender()
  {
  console.log('ww = ' + list );
  for (var i = 0; i &lt; list.length; i++) {
  console.log('lenght = ' + list.length );
  if (list[i].sent == false) 
  {
  console.log('again');
  music();
  list[i].sent=true;
  var link = '#'+list[i].key;
  var notification = new Notification(
  list[i].title, {
  icon: 'ico.ico',
  body: ""+ list[i].key,
  tag:"uniqueTag"
  });
  notification.onclick = function () {
  window.open(link);      
  };
  console.log('ddd = ' + list[i].sent);
  }
      }
    }
  </code></pre>