src/vs/base/browser/ui/contextview/contextview.ts/ContextView/onDOMEvent
class ContextView:	private onDOMEvent(e: Event, onCapture: boolean): void {
		if (this.delegate) {
			if (this.delegate.onDOMEvent) {
				this.delegate.onDOMEvent(e, <HTMLElement>document.activeElement);
			} else if (onCapture && !DOM.isAncestor(<HTMLElement>e.target, this.container)) {
				this.hide();
			}
		}
	}