LayoutTests/http/tests/misc/slow-preload-cancel.html

<p>This test checks that canceling a load when a preload is happening doesn't crash.</p>
<p>If testing manually, if your browser doesn't crash then this was a success.</p>
<button type="button" onclick='window.open("resources/slow-preload-cancel.html");'>Test</button>
<script>
if (window.testRunner) {
    testRunner.setCanOpenWindows();
    testRunner.waitUntilDone();
    testRunner.dumpAsText();
}

window.open("resources/slow-preload-cancel-1.html");
</script>