Don't expand the bar, but the video during resizing...

modules/gui/qt4/components/interface_widgets.cpp

@@ -65,6 +65,7 @@ VideoWidget::VideoWidget( intf_thread_t *_p_i ) : QFrame( NULL ), p_intf( _p_i )
     hide(); setMinimumSize( 16, 16 );
     videoSize.rwidth() = -1;
     videoSize.rheight() = -1;
+    setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
 
     /* Black background is more coherent for a Video Widget IMVHO */
     QPalette plt =  palette();