src/vs/base/common/scrollable.ts/ScrollState/withScrollPosition
class ScrollState:	public withScrollPosition(update: INewScrollPosition): ScrollState {
		return new ScrollState(
			this._forceIntegerValues,
			this.width,
			this.scrollWidth,
			(typeof update.scrollLeft !== 'undefined' ? update.scrollLeft : this.rawScrollLeft),
			this.height,
			this.scrollHeight,
			(typeof update.scrollTop !== 'undefined' ? update.scrollTop : this.rawScrollTop)
		);
	}