chromium/third_party/blink/web_tests/fast/events/resources/popup-blocking-click-in-iframe-otherFrame.html

<html>
    <head>
        <script>
        function prepareEventHandler()
        {
            var spanToClick = document.getElementById('clickable');
            spanToClick.onclick = parent.handleClick;
        }
        </script>
    </head>
    <body style="border: 0; margin: 0" onload="prepareEventHandler()">
        <span id="clickable">Click this text to open a window.</a>
    </body>
</html>