Polymer Template auto-binding issue

by Tomek

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/polymer/0.3.3/platform.js"></script>
<template id="root" is="auto-binding">
    List
    <ul>
        <template repeat="{{ item in list }}">
            <li>{{item.desc}}</li>
        </template>
    </ul>
</template>
<script type="text/javascript">
    var template = document.getElementById("root");

    setTimeout(function() {

        template.list = {
            "list": [{
                "desc": "first"
            }, {
                "desc": "second"
            }, {
                "desc": "third"
            }]
        };
    });
</script>