Adds missing cogl-depth-state-private.h

This file was accidentally missed in the last commit

cogl/cogl-depth-state-private.h

@@ -0,0 +1,32 @@
+/*
+ * Cogl
+ *
+ * An object oriented GL/GLES Abstraction/Utility Layer
+ *
+ * Copyright (C) 2011 Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Robert Bragg <robert@linux.intel.com>
+ */
+
+#ifndef __COGL_DEPTH_STATE_PRIVATE_H
+#define __COGL_DEPTH_STATE_PRIVATE_H
+
+
+#define COGL_DEPTH_STATE_MAGIC 0xDEADBEEF
+
+#endif /* __COGL_DEPTH_STATE_PRIVATE_H */