[gtk+] docs: fix docs for GtkStyleProperties

[William Jon McCann <mccann src gnome org>]

commit 7b14899f4dbdf178f25dff100911e60d273abca4
Author: William Jon McCann <william jon mccann gmail com>
Date:   Tue Jan 21 10:45:43 2014 -0500

    docs: fix docs for GtkStyleProperties

 gtk/gtkstyleproperties.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkstyleproperties.h b/gtk/gtkstyleproperties.h
index 14746ed..0e3f33a 100644
--- a/gtk/gtkstyleproperties.h
+++ b/gtk/gtkstyleproperties.h
@@ -44,12 +44,14 @@ typedef struct _GtkGradient GtkGradient;
 
 struct _GtkStyleProperties
 {
+  /*< private >*/
   GObject parent_object;
   GtkStylePropertiesPrivate *priv;
 };
 
 struct _GtkStylePropertiesClass
 {
+  /*< private >*/
   GObjectClass parent_class;
 
   /* Padding for future expansion */