animation profiling

HTML

<script src="https://github.com/lrbabe/jquery/raw/animateCleanup/src/effects.js"></script>
<button id="run">Animate</button><br/><br/>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>

CSS

div {
    float: left;
    display: inline-block;
    width: 10px;
    height: 10px;
    border: 10px solid black;
    border-width: 0px 20px 20px 0px;
}

JavaScript

$(function() {
    var direction;
    $('#run').click(function() {
        direction = !direction;
        console.profile('a');
        $('div').animate({
            borderTopWidth: direction? 20 : 0,
            borderBottomWidth: direction? 0 : 20,
            borderLeftWidth: direction? 20 : 0,
            borderRightWidth: direction? 0 : 20
        }, 400, function() {
            //console.profileEnd('a');
        });
        console.profileEnd('a');
    });
});