Convert GailCheck(Sub)MenuItem to GtkAccessible classes

This is along the same lines as the previous commit,
with the same caveat.

gtk/gtkcheckmenuitem.c

@@ -33,7 +33,8 @@
 #include "gtkmarshalers.h"
 #include "gtkprivate.h"
 #include "gtkintl.h"
-
+#include "a11y/gtkcheckmenuitemaccessible.h"
+#include "a11y/gtkchecksubmenuitemaccessible.h"
 
 /**
  * SECTION:gtkcheckmenuitem
@@ -102,6 +103,24 @@ G_DEFINE_TYPE_WITH_CODE (GtkCheckMenuItem, gtk_check_menu_item, GTK_TYPE_MENU_IT
                          G_IMPLEMENT_INTERFACE (GTK_TYPE_ACTIVATABLE,
                                                 gtk_check_menu_item_activatable_interface_init))
 
+static AtkObject *
+gtk_check_menu_item_get_accessible (GtkWidget *widget)
+{
+  GObject *object;
+  AtkObject *accessible;
+
+  /* FIXME this is not really right, submenus can come and go */
+  if (gtk_menu_item_get_submenu (GTK_MENU_ITEM (widget)))
+    object = g_object_new (GTK_TYPE_CHECK_SUBMENU_ITEM_ACCESSIBLE, NULL);
+  else
+    object = g_object_new (GTK_TYPE_CHECK_MENU_ITEM_ACCESSIBLE, NULL);
+
+  accessible = ATK_OBJECT (object);
+  atk_object_initialize (accessible, widget);
+
+  return accessible;
+}
+
 static void
 gtk_check_menu_item_class_init (GtkCheckMenuItemClass *klass)
 {
@@ -150,7 +169,8 @@ gtk_check_menu_item_class_init (GtkCheckMenuItemClass *klass)
                                                              GTK_PARAM_READABLE));
 
   widget_class->draw = gtk_check_menu_item_draw;
-  
+  widget_class->get_accessible = gtk_check_menu_item_get_accessible;
+
   menu_item_class->activate = gtk_check_menu_item_activate;
   menu_item_class->hide_on_activate = FALSE;
   menu_item_class->toggle_size_request = gtk_check_menu_item_toggle_size_request;