Как добавить полноэкранный режим YouTube в WebView?

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class YouTubeFragment extends Fragment {


    public YouTubeFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        ((MainActivity)getActivity()).setActionBarTitle("YOUTUBE");

        View v = inflater.inflate(R.layout.fragment_you_tube, container, false);
        WebView webView = (WebView)v.findViewById(R.id.web3);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("https://www.youtube.com/");
        WebSettings webSettings = webView.getSettings();
        webSettings.setDomStorageEnabled(true);
        webSettings.setLoadWithOverviewMode(true); webSettings.setUseWideViewPort(true);
        webSettings.setSupportZoom(true); 
        
        return v;
    }

}