src/vs/workbench/browser/parts/editor/breadcrumbsPicker.ts/BreadcrumbsPicker/_layout
class BreadcrumbsPicker:	protected _layout(): void {

		const headerHeight = 2 * this._layoutInfo.arrowSize;
		const treeHeight = Math.min(this._layoutInfo.maxHeight - headerHeight, this._tree.contentHeight);
		const totalHeight = treeHeight + headerHeight;

		this._domNode.style.height = `${totalHeight}px`;
		this._domNode.style.width = `${this._layoutInfo.width}px`;
		this._arrow.style.top = `-${2 * this._layoutInfo.arrowSize}px`;
		this._arrow.style.borderWidth = `${this._layoutInfo.arrowSize}px`;
		this._arrow.style.marginLeft = `${this._layoutInfo.arrowOffset}px`;
		this._treeContainer.style.height = `${treeHeight}px`;
		this._treeContainer.style.width = `${this._layoutInfo.width}px`;
		this._tree.layout(treeHeight, this._layoutInfo.width);
	}