src/vs/platform/menubar/electron-main/menubar.ts/Menubar/registerListeners
class Menubar:	private registerListeners(): void {
		// Keep flag when app quits
		this.lifecycleMainService.onWillShutdown(() => this.willShutdown = true);

		// Listen to some events from window service to update menu
		this.windowsMainService.onDidChangeWindowsCount(e => this.onDidChangeWindowsCount(e));
		this.nativeHostMainService.onDidBlurWindow(() => this.onDidChangeWindowFocus());
		this.nativeHostMainService.onDidFocusWindow(() => this.onDidChangeWindowFocus());
	}