chromium/third_party/blink/web_tests/fast/events/download-on-alt-click.html

<!doctype html>
<script>
function test()
{
    if (window.testRunner) {
        testRunner.dumpAsText();
        testRunner.waitUntilDone();
        testRunner.waitUntilExternalURLLoad();

        var a = document.querySelector("#link");
        eventSender.mouseMoveTo(a.offsetLeft + 10, a.offsetTop + 10);
        eventSender.mouseDown(0, ['altKey']);
        eventSender.mouseUp(0, ['altKey']);
    }
}
</script>
<body onload="test()">
<p>Tests that hitting alt-click results in downloading link. Test passes if a download is observed.</p>
<a href="resources/notify-done.html" id="link">link</a>
</body>