Kill chrome process

Kill chrome process

I created a new project in Android. We use the following code:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.web);
webView = (WebView) findViewById(R.id.webView);
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl("http://t.co/YoHe3NKrJH");
He is opening Chrome.
I need to close it automatically after 10s.