test-paint-wrapper: Request ARGB visuals on GLX

If we are on GLX we have to request ARGB visuals, otherwise Clutter will
not do it by itself.

tests/interactive/test-paint-wrapper.c

@@ -1,3 +1,7 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #include <gmodule.h>
 #include <clutter/clutter.h>
 
@@ -10,6 +14,10 @@
 #include <stdlib.h>
 #include <glib.h>
 
+#ifdef HAVE_CLUTTER_GLX
+#include "clutter/x11/clutter-x11.h"
+#endif
+
 #define NHANDS  6
 
 typedef struct SuperOH
@@ -195,6 +203,10 @@ test_paint_wrapper_main (int argc, char *argv[])
 
   error = NULL;
 
+#ifdef HAVE_CLUTTER_GLX
+  clutter_x11_set_use_argb_visual (TRUE);
+#endif
+
   clutter_init_with_args (&argc, &argv,
                           NULL,
                           super_oh_entries,