title: Show popup menu on `ActionBar` item click
body: <p>I have an <code>ActionBar</code> with an action item on it. After clicking on the action item, I want to show a popup menu.
  I implemented this method, but I want to anchor it to the action item or to the <code>ActionBar</code>, not to any view from layout. How to get some kind of view to anchor it from <code>MenuItem</code>?</p>
  
  <pre><code>public boolean onOptionsItemSelected(MenuItem item) {
      PopupMenu popupMenu = new PopupMenu(this, ??????); // What view goes here?
      popupMenu.inflate(R.menu.counters_overflow);
      popupMenu.show();
      // ...
      return true;
  }
  </code></pre>