ScrollBar = function(parent) {
    this.element = dom.createElement("div");
    this.element.className = "ace_sb";

    this.inner = dom.createElement("div");
    this.element.appendChild(this.inner);

    parent.appendChild(this.element);

    // in OSX lion the scrollbars appear to have no width. In this case resize
    // the to show the scrollbar but still pretend that the scrollbar has a width
    // of 0px
    // in Firefox 6+ scrollbar is hidden if element has the same width as scrollbar
    // make element a little bit wider to retain scrollbar when page is zoomed 
    this.width = dom.scrollbarWidth(parent.ownerDocument);
    this.element.style.width = (this.width || 15) + 5 + "px";

    event.addListener(this.element, "scroll", this.onScroll.bind(this));
}
new ScrollBar(parent)
- parent (DOMElement): A DOM element 

Creates a new `ScrollBar`. `parent` is the owner of the scroll bar.