[mutter] orientation-manager: Expose the number of valid orientations

[Marge Bot <marge-bot src gnome org>]

commit f1228c4a51c0234daa5c6f98d874099635bd94b3
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Tue May 5 17:51:48 2020 +0200

    orientation-manager: Expose the number of valid orientations
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1233>

 src/backends/meta-orientation-manager.h | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/backends/meta-orientation-manager.h b/src/backends/meta-orientation-manager.h
index 9ae87957d4..9ceefb81ea 100644
--- a/src/backends/meta-orientation-manager.h
+++ b/src/backends/meta-orientation-manager.h
@@ -32,6 +32,7 @@ typedef enum
   META_ORIENTATION_LEFT_UP,
   META_ORIENTATION_RIGHT_UP
 } MetaOrientation;
+#define META_N_ORIENTATIONS (META_ORIENTATION_RIGHT_UP + 1)
 
 #define META_TYPE_ORIENTATION_MANAGER (meta_orientation_manager_get_type ())
 G_DECLARE_FINAL_TYPE (MetaOrientationManager, meta_orientation_manager,