[gtk+] Add a way to test titlebars in dark theme

[Matthias Clasen <matthiasc src gnome org>]

commit eed2799bfb64f073531e601c4ff2bfbf845b236e
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Aug 25 23:18:04 2013 -0400

    Add a way to test titlebars in dark theme

 tests/testtitlebar.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/tests/testtitlebar.c b/tests/testtitlebar.c
index 107f705..1d21649 100644
--- a/tests/testtitlebar.c
+++ b/tests/testtitlebar.c
@@ -13,6 +13,9 @@ main (int argc, char *argv[])
 
   gtk_init (NULL, NULL);
 
+  if (g_getenv ("DARK"))
+    g_object_set (gtk_settings_get_default (), "gtk-application-prefer-dark-theme", TRUE, NULL);
+
   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
   gtk_window_set_default_size (GTK_WINDOW (window), 600, 400);