textarea-placeholder-set-value.html

<html>
<head>
  <script type="text/javascript" charset="utf-8">
    function runTest()
    {
      document.getElementById('text').value = 'New text';
    }
  </script>
</head>
<body onload="runTest()">
  <p>Test for <a href="https://bugs.webkit.org/show_bug.cgi?id=21248">https://bugs.webkit.org/show_bug.cgi?id=21248</a>.</p>

  <textarea id="text" placeholder="Placeholder text"></textarea>
</body>
</html>

chromium/third_party/blink/web_tests/fast/forms/textarea/textarea-placeholder-set-value.html