Unable to Full Screen Youtube Video Inside Custom Webview

Update

I updated my question to hide sensitive code.

If there is still any confusion, then I am in the comments.

Question

I wrote my own webview to play YouTube videos embedded in my website to go full screen.

But its still not working .. kind help

   public class MainActivity extends Activity  implements OnClickListener {

          final Context context = this;
        private WebView webView;
         private ImageButton btnrefresh;    
         private TextView txtrefresh;
           private myWebChromeClient mWebChromeClient;
         private Menu optionsMenu;
         private WebChromeClient.CustomViewCallback customViewCallback;
            private View mCustomView;       
            private FrameLayout customViewContainer;


        @SuppressWarnings("deprecation")
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            //Tushar
              customViewContainer = (FrameLayout) findViewById(R.id.customViewContainer);
            //Tushar
            //define button 
            btnrefresh = (ImageButton) findViewById(R.id.imageButton1);

            btnrefresh.setOnClickListener(this);
            btnrefresh.setVisibility(View.GONE);

            //define textView
            txtrefresh = (TextView)findViewById((R.id.textView1));
            txtrefresh.setVisibility(View.GONE);


            if(isConnected())
            {

                webView = (WebView) findViewById(R.id.webView1);
                webView.getSettings().setJavaScriptEnabled(true);       
                   webView.getSettings().setAppCacheEnabled(true);

                    webView.getSettings().setRenderPriority(RenderPriority.HIGH);
                    webView.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
                    webView.getSettings().setSaveFormData(true);
            //  webView.getSettings().setPluginState(PluginState.ON);
              webView.setWebViewClient(new WebViewClient()
              {
              @Override
              public boolean shouldOverrideUrlLoading(WebView view, String url) {


                  if (url.startsWith("mailto:")) {
                      sendEmail(url.substring(7));
                      return true;
                  }

                  return false;
              }

            });


                initWebView(webView);                         
                webView.loadUrl("http://Example.com/");             

                }


            else
            {

            RelativeLayout rel = (RelativeLayout)findViewById(R.id.relativelayout1);
            rel.setOnClickListener(new View.OnClickListener(){
               @Override
               public void onClick(View v){
                 refresh();
               }
           });
                btnrefresh.setVisibility(View.VISIBLE); 
                txtrefresh.setVisibility(View.VISIBLE);
                Toast.makeText(getBaseContext(), "No Internet Connection !!", Toast.LENGTH_SHORT).show();


            }       
        }

        public boolean inCustomView() {
            return (mCustomView != null);
        }

        public void hideCustomView() {
            mWebChromeClient.onHideCustomView();
        }

        @Override
        protected void onPause() {
            super.onPause();    //To change body of overridden methods use File | Settings | File Templates.
            webView.onPause();
        }

        @Override
        protected void onResume() {
            super.onResume();    //To change body of overridden methods use File | Settings | File Templates.
            webView.onResume();
        }

        @Override
        protected void onStop() {
            super.onStop();    //To change body of overridden methods use File | Settings | File Templates.
            if (inCustomView()) {
                hideCustomView();
            }
        }

        //tushar
        class myWebChromeClient extends WebChromeClient {
            private Bitmap mDefaultVideoPoster;
            private View mVideoProgressView;

            @Override
            public void onShowCustomView(View view, int requestedOrientation, CustomViewCallback callback) {
               onShowCustomView(view, callback);    //To change body of overridden methods use File | Settings | File Templates.
            }

            @Override
            public void onShowCustomView(View view,CustomViewCallback callback) {

                // if a view already exists then immediately terminate the new one
                if (mCustomView != null) {
                    callback.onCustomViewHidden();
                    return;
                }
                mCustomView = view;
                webView.setVisibility(View.GONE);
                customViewContainer.setVisibility(View.VISIBLE);
                customViewContainer.addView(view);
                customViewCallback = callback;
            }

            @Override
            public View getVideoLoadingProgressView() {

                if (mVideoProgressView == null) {
                    LayoutInflater inflater = LayoutInflater.from(MainActivity.this);
                    mVideoProgressView = inflater.inflate(R.layout.video_progress, null);
                }
                return mVideoProgressView;
            }

            @Override
            public void onHideCustomView() {
                super.onHideCustomView();    //To change body of overridden methods use File | Settings | File Templates.
                if (mCustomView == null)
                    return;

                webView.setVisibility(View.VISIBLE);
                customViewContainer.setVisibility(View.GONE);

                // Hide the custom view.
                mCustomView.setVisibility(View.GONE);

                // Remove the custom view from its container.
                customViewContainer.removeView(mCustomView);
                customViewCallback.onCustomViewHidden();

                mCustomView = null;
            }
        }