chromium/android_webview/test/data/autofill/form_username.html

<html>
  <body>
    <form action='a.html' name='formname' id='formid'>
      <input type='text' id='text1' name='username'
             placeholder='[email protected]'
             autocomplete='username name'>
      <input type='submit'>
    </form>
  </body>
</html>