[gtk+] Rename the modelbutton style class

[Matthias Clasen <matthiasc src gnome org>]

commit baaf201f2a9f1b897eb881e4380d5c4a9d050369
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Apr 27 18:48:06 2014 -0400

    Rename the modelbutton style class
    
    This is not a great name to use in themes; instead, add the
    menuitem class, so themes can use .button.menuitem for styles
    that are specific to menuitem-like buttons.

 gtk/gtkmodelbutton.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkmodelbutton.c b/gtk/gtkmodelbutton.c
index b5fee44..bb74209 100644
--- a/gtk/gtkmodelbutton.c
+++ b/gtk/gtkmodelbutton.c
@@ -687,7 +687,8 @@ gtk_model_button_init (GtkModelButton *button)
   gtk_container_add (GTK_CONTAINER (button->box), button->image);
   gtk_container_add (GTK_CONTAINER (button->box), button->label);
   gtk_container_add (GTK_CONTAINER (button), button->box);
-  gtk_style_context_add_class (gtk_widget_get_style_context (GTK_WIDGET (button)), "modelbutton");
+  gtk_style_context_add_class (gtk_widget_get_style_context (GTK_WIDGET (button)),
+                               GTK_STYLE_CLASS_MENUITEM);
 }
 
 GtkWidget *