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chromium/third_party/blink/web_tests/http/tests/navigation/form-submit-from-opened-window.html 

<body>
<script>
if (window.testRunner) {
    testRunner.waitUntilDone();
    testRunner.dumpAsText();
    testRunner.setPopupBlockingEnabled(false);
}

window.name = "start";
window.open("resources/form-submit-from-opened-window-helper.html");
</script>
</body>