chromium/third_party/blink/web_tests/fast/events/resources/subframe-xmlhttprequest.html

<!DOCTYPE html>
<html>
<head>
    <script>
        function test() {
            window.top.console.log('XMLHttpRequest in subframe-1 created');
            var xhr = new XMLHttpRequest();
            xhr.open('GET', 'about:empty', true);
        }
    </script>
</head>
<body>
I am subframe-1
</body>
</html>