src/vs/workbench/electron-sandbox/parts/titlebar/menubarControl.ts/NativeMenubarControl/getAdditionalKeybindings
class NativeMenubarControl:	private getAdditionalKeybindings(): { [id: string]: IMenubarKeybinding } {
		const keybindings: { [id: string]: IMenubarKeybinding } = {};
		if (isMacintosh) {
			const keybinding = this.getMenubarKeybinding('workbench.action.quit');
			if (keybinding) {
				keybindings['workbench.action.quit'] = keybinding;
			}
		}

		return keybindings;
	}