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

<!--
  Form with prefilled username and password fields.
 -->
<html>
<body>
<form method="POST" action="done.html" onsubmit="return true;" id="testform">
  <input type="text" id="username_field" name="username_field" value="some_username">
  <input type="password" id="password_field" name="password_field" value="some_password">
  <input type="submit" id="input_submit_button" name="input_submit_button">
</form>
</body>
</html>