src/vs/workbench/services/host/electron-sandbox/nativeHostService.ts/WorkbenchHostService/hadLastFocus
class WorkbenchHostService:	async hadLastFocus(): Promise<boolean> {
		const activeWindowId = await this.nativeHostService.getActiveWindowId();

		if (typeof activeWindowId === 'undefined') {
			return false;
		}

		return activeWindowId === this.nativeHostService.windowId;
	}