[gnome-boxes] topbar: Make display_toolbar public

[Felipe Borges <felipeborges src gnome org>]

commit 964c40234bbe710cf107526d76ebb57d40c3aa87
Author: Visarion Alexandru <viorel visarion gmail com>
Date:   Sun Nov 5 22:11:00 2017 +0000

    topbar: Make display_toolbar public
    
    We need this for a future patch, so that we can control the
    behaviour of the file transfer button from the DisplayPage class.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=762321

 src/topbar.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/topbar.vala b/src/topbar.vala
index 4675ab5f..d8d63ff9 100644
--- a/src/topbar.vala
+++ b/src/topbar.vala
@@ -19,7 +19,7 @@
     [GtkChild]
     private SelectionToolbar selection_toolbar;
     [GtkChild]
-    private DisplayToolbar display_toolbar;
+    public DisplayToolbar display_toolbar;
 
     private AppWindow window;