chromium/third_party/blink/web_tests/fast/forms/select/input-select-after-resize.html

<!DOCTYPE html>
<script src="../resources/picker-common.js"></script>
<select>
    <option value="1" selected></option>
    <option value="2"></option>
</select>
<script>
    addEventListener('load', function() {
        // This test passes if the menu dropdown is drawn attached to the
        // <select> box. This is a test for crbug.com/638671.
        if (window.testRunner)
            testRunner.waitUntilDone();

        window.resizeBy(0, 0);

        // Wait a frame so that the move has a chance to be ack'd by the
        // browser.
        window.requestAnimationFrame(function() {
            var select = document.getElementsByTagName('select')[0];
            select.focus();
            eventSender.keyDown("ArrowDown", ["altKey"]);
            testRunner.notifyDone();
        });
    });
</script>