chromium/chrome/test/data/form_that_posts_to_echoall.html

<!DOCTYPE html>
<html>
  <head></head>
  <body>
    <form id="form" method="POST" action="/echoall">
      <input type="text" name="text" value="value">
      <input type="submit">
    </form>
    <form id="form-multipart-form-data" method="POST" action="/echoall" enctype="multipart/form-data">
      <input type="text" name="text" value="value">
      <input type="submit">
    </form>
  </body>
</html>