chromium/chrome/test/data/autofill/dynamic_form_element_invalid_multiple_noname_forms.html

<!-- A page that is used to test that a dynamic form fill feature works properly.
Two nameless forms whose fields have identical names, and the name field goes
invalid when the country is changed.-->
<body>
  <form>
    Name: <input type="text" name="firstname" id="firstname_1" autocomplete="given-name"><br>
   <input type="text" name="firstname" id="firstname_2" autocomplete="given-name" style="display: none"><br>
    Address: <input type="text" name="address1" id="address1_3"><br>
    Country: <select name="country" id="country_4" onchange="CountryChanged()">
      <option value="CA">Canada</option>
      <option value="US">United States</option>
    </select>
    <input type="reset" value="Reset">
    <input type="submit" value="Submit" id="profile_submit">
  </form>
    <form>
    Name: <input type="text" name="firstname" id="firstname_5" autocomplete="given-name"><br>
   <input type="text" name="firstname" id="firstname_6" autocomplete="given-name" style="display: none"><br>
    Address: <input type="text" name="address1" id="address1_7"><br>
    Country: <select name="country" id="country_8" onchange="CountryChanged()">
      <option value="CA">Canada</option>
      <option value="US">United States</option>
    </select>
    <input type="reset" value="Reset">
    <input type="submit" value="Submit" id="profile_submit">
  </form>
</body>

<script>
function CountryChanged() {
  // Reset the value of the address field.
  var address1 = document.getElementById('address1_7');
  address1.value = '';
  window['refill'] = true;
  console.log('An event happened that should trigger a refill.');

  // Change the element that triggered the autofill. Remove it, and make another
  // field visible. This is to test if the autofill can handle the case where
  // the clicked on element is no longer valid.
  var first_name_input = document.getElementById("firstname_5");
  first_name_input.parentNode.removeChild(first_name_input);

  var name_later = document.getElementById("firstname_6");
  name_later.removeAttribute('style');
}
</script>