more polyfill

var webComponentsSupported = ('registerElement' in document
    && 'import' in document.createElement('link')
    && 'content' in document.createElement('template'));

//lazy load the polyfills if needed
if (!webComponentsSupported) {
    var script = document.createElement('script');
    script.async = true;
    srcipt.src = 'webcomponents-lite.min.js';
    script.onload = finishLazyLoading;
    document.head.appendChild(script);
} else {
    finishLazyLoading();
}

see https://github.com/PolymerLabs/zuperkulblog-progressive/blob/master/app/static/scripts/app.js