src/vs/base/browser/ui/scrollbar/horizontalScrollbar.ts/HorizontalScrollbar/onDidScroll
class HorizontalScrollbar:	public onDidScroll(e: ScrollEvent): boolean {
		this._shouldRender = this._onElementScrollSize(e.scrollWidth) || this._shouldRender;
		this._shouldRender = this._onElementScrollPosition(e.scrollLeft) || this._shouldRender;
		this._shouldRender = this._onElementSize(e.width) || this._shouldRender;
		return this._shouldRender;
	}