[gtk+/gtk-3-20] gtk3-demo: Add a close button to the markup window

[Matthias Clasen <matthiasc src gnome org>]

commit adcbd8add9ca16cf0b3a3d8d13b6dbb41be3e4be
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri May 6 20:50:38 2016 -0400

    gtk3-demo: Add a close button to the markup window

 demos/gtk-demo/markup.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/demos/gtk-demo/markup.c b/demos/gtk-demo/markup.c
index 5e856b6..486b454 100644
--- a/demos/gtk-demo/markup.c
+++ b/demos/gtk-demo/markup.c
@@ -68,6 +68,7 @@ do_markup (GtkWidget *do_widget)
       g_signal_connect (show_source, "toggled", G_CALLBACK (source_toggled), stack);
 
       header = gtk_header_bar_new ();
+      gtk_header_bar_set_show_close_button (GTK_HEADER_BAR (header), TRUE);
       gtk_header_bar_pack_start (GTK_HEADER_BAR (header), show_source);
       gtk_widget_show_all (header);
       gtk_window_set_titlebar (GTK_WINDOW (window), header);