[gtk/a11y/atcontext-realize] Propagate accessible-role to backend

[Matthias Clasen <matthiasc src gnome org>]

commit 828a067b2b1b9be06f953e1aeddc3e3d94fffd4b
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Nov 4 11:53:07 2020 -0500

    Propagate accessible-role to backend
    
    We want to allow setting the accessible role as long
    as the context is unrealized, so we need to propagate
    the new role.

 gtk/gtkwidget.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 9c4f78ad57..e81488c4fb 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -1734,6 +1734,8 @@ gtk_widget_set_property (GObject         *object,
       if (priv->at_context == NULL || !gtk_at_context_is_realized (priv->at_context))
         {
           priv->accessible_role = g_value_get_enum (value);
+          if (priv->at_context)
+            g_object_set (priv->at_context, "accessible-role", priv->accessible_role, NULL);
           g_object_notify_by_pspec (object, pspec);
         }
       else