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

<!-- A page that is used to test that a dynamic form fill feature works properly. -->
<body>
  <form name="addr1.1" id="form1" action="https://example.com/" method="post">
    Name: <input type="text" name="firstname" id="firstname" autocomplete="given-name"><br>
   <input type="text" name="firstname" id="firstname2" autocomplete="given-name" style="display: none"><br>
    Address: <input type="text" name="address1" id="address1"><br>
    City: <input type="text" name="city" id="city"><br>
    <input type="text" name="state_us" id="state_us" style="display: none;" autocomplete="region"><br>
    Zip: <input name="zip" id="zip"> <br>
    Country: <select name="country" id="country" onchange="CountryChanged()">
      <option value="CA">Canada</option>
      <option value="US">United States</option>
    </select> <br>
    Company: <input name="company" id="company"> <br>
    Email: <input name="email" id="email"> <br>
    Phone: <input name="phone" id="phone"> <br>
    <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');
  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  // the clicked on element is no longer valid.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");
  first_name_input.parentNode.removeChild(first_name_input);

  var name_later = document.getElementById("firstname2");
  name_later.removeAttribute('style');
}
</script>