http/tests/security/calling-versus-current.html

<iframe src="resources/innocent-victim.html"></iframe>
<div id="console">FAIL</div>
<script>
if (window.testRunner)
    testRunner.dumpAsText();

window.onload = function() {
    window.f = frames[0].atob;
    document.domain = "0.0.1";
    if (btoa(window.f("PASS")) == "PASS")
        document.getElementById("console").innerHTML = "PASS"
}
</script>