src/vs/editor/common/viewLayout/viewLayout.ts/ViewLayout/changeWhitespace
class ViewLayout:	public changeWhitespace(callback: (accessor: IWhitespaceChangeAccessor) => void): boolean {
		const hadAChange = this._linesLayout.changeWhitespace(callback);
		if (hadAChange) {
			this.onHeightMaybeChanged();
		}
		return hadAChange;
	}