LayoutTests/http/tests/websocket/tests/hybi/contentextensions/upgrade-worker.html

<script>

if (window.testRunner) {
    testRunner.waitUntilDone();
    testRunner.dumpAsText();
}

function endTest() {
    if (window.testRunner)
        testRunner.notifyDone();
}

function startsWith(str, prefix) {
    return str.indexOf(prefix) == 0;
}

var worker = new Worker("resources/upgrade-worker.js");
worker.onmessage = function (event)
{
    var message = event.data;
    console.log(message);
    if (startsWith(message, "PASS") || startsWith(message, "FAIL"))
		endTest();
};
</script>