third_party/WebKit/LayoutTests/http/tests/security/mixedContent/resources/frame-preloads-insecure-image.html

<script src="https://127.0.0.1:8080/resources/slow-script.pl?delay=3000"></script>
<img src="http://example.test:8080/security/resources/compass.jpg">
<script>
window.onload = function() {
    if (window.opener)
        window.opener.postMessage('done', '*');
};
</script>