page_displays_insecure_form_in_iframe.html

<html>
<head><title>Page that displays an insecure form inside an iframe</title>
<script>
function submitForm() {
  subframe = document.getElementById("insecureFormFrame");
  subframe.contentWindow.submitForm();
}
</script>
</head>
<body>
This page contains an iframe, which contains a form that targets a non-secure URL,
causing insecure content.<br>
<iframe id="insecureFormFrame" src="https://REPLACE_WITH_HOST_AND_PORT/ssl/page_displays_insecure_form.html"></iframe>
</body>
</html>

chromium/chrome/test/data/ssl/page_displays_insecure_form_in_iframe.html