src/vs/editor/common/viewModelEventDispatcher.ts/ScrollChangedEvent/constructor
class ScrollChangedEvent:	constructor(
		oldScrollWidth: number, oldScrollLeft: number, oldScrollHeight: number, oldScrollTop: number,
		scrollWidth: number, scrollLeft: number, scrollHeight: number, scrollTop: number,
	) {
		this._oldScrollWidth = oldScrollWidth;
		this._oldScrollLeft = oldScrollLeft;
		this._oldScrollHeight = oldScrollHeight;
		this._oldScrollTop = oldScrollTop;

		this.scrollWidth = scrollWidth;
		this.scrollLeft = scrollLeft;
		this.scrollHeight = scrollHeight;
		this.scrollTop = scrollTop;

		this.scrollWidthChanged = (this._oldScrollWidth !== this.scrollWidth);
		this.scrollLeftChanged = (this._oldScrollLeft !== this.scrollLeft);
		this.scrollHeightChanged = (this._oldScrollHeight !== this.scrollHeight);
		this.scrollTopChanged = (this._oldScrollTop !== this.scrollTop);
	}