<!DOCTYPE html>
<html class='reftet-wait'>
  <!-- Test: if textarea is valid and its value has been modified,
             it should be affected by :-moz-ui-valid pseudo-class. -->
  <link rel='stylesheet' type='text/css' href='style.css'>
  <body onload="document.getElementById('t').value = 'foo';
                document.documentElement.className = '';">
    <textarea id='t' class='valid' required></textarea>
  </body>
</html>