chromium/chrome/test/data/session_restore/post.html

<!DOCTYPE html>
<html>
<head>
<script>
function onLoad() {
  document.getElementById('posted-text').value = 'text-entered';
  document.getElementById('form-to-submit').submit();
}
</script>
</head>
<body onload="setTimeout(onLoad, 0);">
<form id="form-to-submit" action="posted.php" method="post"
      enctype="multipart/form-data">
Text to input: <input id="posted-text" type="text" name="posted-text"/><br>
<input type="submit" value="Submit" />
</form>
</body>
</html>