[gtk+/gtk-3-22] GtkFrame: Fix shadow after theme changes

[Daniel Boles <dboles src gnome org>]

commit 2e4fb454350eae7a84a96e56d9fe9e8f0c564072
Author: Florian Müllner <florian muellner gmail com>
Date:   Tue Feb 21 11:11:10 2017 +0100

    GtkFrame: Fix shadow after theme changes
    
    Commit 0c20604932f changed the theme to expect the .flat class on
    the frame node rather than the border one, but didn't update the
    code that applies the style according to the :shadow-type property.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=779005

 gtk/gtkframe.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkframe.c b/gtk/gtkframe.c
index ed2ea68..317bae2 100644
--- a/gtk/gtkframe.c
+++ b/gtk/gtkframe.c
@@ -681,9 +681,9 @@ gtk_frame_set_shadow_type (GtkFrame      *frame,
       priv->shadow_type = type;
 
       if (type == GTK_SHADOW_NONE)
-        gtk_css_gadget_add_class (priv->border_gadget, GTK_STYLE_CLASS_FLAT);
+        gtk_css_gadget_add_class (priv->gadget, GTK_STYLE_CLASS_FLAT);
       else
-        gtk_css_gadget_remove_class (priv->border_gadget, GTK_STYLE_CLASS_FLAT);
+        gtk_css_gadget_remove_class (priv->gadget, GTK_STYLE_CLASS_FLAT);
 
       g_object_notify_by_pspec (G_OBJECT (frame), frame_props[PROP_SHADOW_TYPE]);
     }