<style>
a { display: none; }
a:after { content: "after"; }
div:hover a { display: inline-block }
</style>
<script>
function test()
{
    var target = document.getElementById("target");
    if (window.testRunner)
        testRunner.waitUntilDone();
    if (window.eventSender)
        eventSender.mouseMoveTo(target.offsetLeft + 10, target.offsetTop + 10);
}
function done()
{
    if (window.testRunner)
        testRunner.notifyDone();
}
</script>
<body onload="test()">
<div id="target" onmouseenter="done()">target <a></a></div>