tests: Exit test when main window is closed

tests/animated-revealing.c

@@ -38,6 +38,7 @@ main(int argc, char **argv)
     }
 
   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+  g_signal_connect (window, "destroy", gtk_main_quit, NULL);
   frame_stats_ensure (GTK_WINDOW (window));
 
   revealer = gtk_revealer_new ();