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