src/vs/base/browser/ui/grid/gridview.ts/GridView/getViewSize
class GridView:	getViewSize(location?: number[]): IViewSize {
		if (!location) {
			return { width: this.root.width, height: this.root.height };
		}

		const [, node] = this.getNode(location);
		return { width: node.width, height: node.height };
	}