code: function runPicturefill() {
      picturefill();
      var intervalId = setInterval( function(){
        // When the document has finished loading, stop checking for new images
        // https://github.com/ded/domready/blob/master/ready.js#L15
        w.picturefill();
        if ( /^loaded|^i|^c/.test( doc.readyState ) ) {
          clearInterval( intervalId );
          return;
        }
      }, 250 );
      if( w.addEventListener ){
        var resizeThrottle;
        w.addEventListener( "resize", function() {
          w.clearTimeout( resizeThrottle );
          resizeThrottle = w.setTimeout( function(){
            picturefill({ reevaluate: true });
          }, 60 );
        }, false );
      }
    }
docs: Sets up picture polyfill by polling the document and running
  the polyfill every 250ms until the document is ready.
  Also attaches picturefill on resize