Bug 506254 plugin_client_message_filter never used Display *dpy

r=roc

widget/src/gtk2/nsWindow.cpp

@@ -5624,9 +5624,6 @@ plugin_client_message_filter(GdkXEvent *gdk_xevent,
     // to set the focus to the focus proxy. To prevent this happen
     // while the focus is on the plugin, we filter the WM_TAKE_FOCUS
     // out.
-    Display *dpy ;
-    dpy = GDK_WINDOW_XDISPLAY((GdkWindow*)(gPluginFocusWindow->
-                GetNativeData(NS_NATIVE_WINDOW)));
     if (gdk_x11_get_xatom_by_name("WM_PROTOCOLS")
             != xevent->xclient.message_type) {
         return return_val;