code: function getScrollOffset(delta) {
          var itemSize = 0,
              size     = 0;
  
          itemSize = getCarouselItemSize.call(this);
          size = itemSize * delta;
  
          return size;
      }
docs: Return the scrolling offset size given the number of elements to
  scroll.
  
  @method getScrollOffset
  @param delta {Number} The delta number of elements to scroll by.
  @private