[gnome-builder] GbDocument: add helper to get seconds since known mtime.

[Christian Hergert <chergert src gnome org>]

commit b621f1e46bb8c958cf9f2005f71b5af643529447
Author: Christian Hergert <christian hergert me>
Date:   Fri Dec 12 16:27:49 2014 -0800

    GbDocument: add helper to get seconds since known mtime.

 src/documents/gb-document-private.h |   30 ++++++++++++++++++++++++++++++
 1 files changed, 30 insertions(+), 0 deletions(-)
---
diff --git a/src/documents/gb-document-private.h b/src/documents/gb-document-private.h
new file mode 100644
index 0000000..bf2f6c0
--- /dev/null
+++ b/src/documents/gb-document-private.h
@@ -0,0 +1,30 @@
+/* gb-document-private.h
+ *
+ * Copyright (C) 2014 Christian Hergert <christian hergert me>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GB_DOCUMENT_PRIVATE_H
+#define GB_DOCUMENT_PRIVATE_H
+
+#include "gb-document.h"
+
+G_BEGIN_DECLS
+
+G_GNUC_INTERNAL glong _gb_document_get_seconds_since_last_save_or_load (GbDocument *document);
+
+G_END_DECLS
+
+#endif /* GB_DOCUMENT_PRIVATE_H */