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chromium/third_party/blink/web_tests/http/tests/security/postMessage/resources/post-message-listener.html 

<!DOCTYPE html>
<html>
<body>
<div>window.location.href = <script>document.write(window.location.href);</script></div>
<script>
function recv(e) {
    var msg = 'Received message: data="' + e.data + '" origin="' + e.origin + '"';
    top.postMessage(msg, '*');
}

addEventListener("message", recv, false);
</script>
</body>
</html>