code: function (horizontalPadding) {
          var de = document.documentElement,
              body = document.body,
              el, initData;
  
          // Create a div to figure out the size of the view-port across browsers
          el = document.createElement('div');
          el.style.position = "fixed";
          el.style.top = 0;
          el.style.left = 0;
          el.style.bottom = 0;
          el.style.right = 0;
          de.insertBefore(el, de.firstChild);
  
          initData = {
              bodyOverflow: body.style.overflow,
              bodyWidth: body.style.width,
              bodyHeight: body.style.height,
              documentWidth: Math.max(body.scrollWidth, body.offsetWidth, de.clientWidth, de.scrollWidth, de.offsetWidth),
              devicePixelRatio: window.devicePixelRatio || 1,
              padding: body.style.padding,
              viewPortWidth: el.offsetWidth,
  			horizontalPadding: horizontalPadding
          };
  
          de.removeChild(el);
  
          // Remove scrollbars
          body.style.overflow = 'hidden';
  
          // Make document only one pixel height and as wide as the view-port
          body.style.width = (initData.viewPortWidth - horizontalPadding) + 'px';
          body.style.height = '1px';
          body.style.minHeight = '0';
          body.style.minWidth = '0';
  
          de.style.width = (initData.viewPortWidth - horizontalPadding) + 'px';
          de.style.height = '1px';
          de.style.minHeight = '0';
          de.style.minWidth = '0';
          de.style.overflow = 'hidden';
  
          return JSON.stringify(initData);
      }
docs: This is done to fix some issues with Chrome: http://www.quirksmode.org/blog/archives/2012/06/devicepixelrati.html The property window.devicePixelRatio cannot be trusted in most browsers (if even available). 
  Initialize the device-pixel-ratio determination,
  collecting information that need to be reverted later on and
  modifying the document for device-pixel-ratio data.
  
  @method init
  @param {int} horizontalPadding