wxMac's wxListBox was missing GetDefaultAttributes() to accompany its GetClassDefaultAttributes()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@52039 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/mac/carbon/listbox.h

@@ -101,6 +101,11 @@ public:
 
     virtual void EnsureVisible(int n);
 
+    virtual wxVisualAttributes GetDefaultAttributes() const
+    {
+        return GetClassDefaultAttributes(GetWindowVariant());
+    }
+
     // wxCheckListBox support
     static wxVisualAttributes
     GetClassDefaultAttributes(wxWindowVariant variant = wxWINDOW_VARIANT_NORMAL);