<!DOCTYPE html>
<html class="reftest-wait">
  <head>
    <script>
      function doTest() {
        document.getElementById('t').removeAttribute('readonly');
        document.documentElement.className='';
      }
      document.addEventListener("MozReftestInvalidate", doTest);
    </script>
  </head>
  <!-- Test: if textarea is no longer readonly, it is candidate for constraint
             validation and should be affected by :invalid pseudo-class. -->
  <link rel='stylesheet' type='text/css' href='style.css'>
  <body>
    <textarea class='invalid' id='t' readonly required></textarea>
  </body>
</html>