chromium/chrome/test/data/password/password_form_with_hash.html

<html>

<script>
function hashPassword() {
  document.getElementById("password_field").value = "hashed_value";
}
</script>

<body>
<form method="POST" target="_top" action="done.html"
      onsubmit="hashPassword(); return true;" id="testform">
  <input type="text" id="username_field" name="username_field">
  <input type="password" id="password_field" name="password_field">
  <input type="submit" id="input_submit_button" name="input_submit_button">
</form>
</body>
</html>