src/vs/workbench/electron-sandbox/window.ts/NativeWindow/onDidAllEditorsClose
class NativeWindow:	private onDidAllEditorsClose(): void {
		const visibleEditorPanes = this.editorService.visibleEditorPanes.length;
		if (visibleEditorPanes === 0) {
			this.nativeHostService.closeWindow();
		}
	}