[clutter] Add missing _cogl_winsys_has_feature prototype

[Robert Bragg <rbragg src gnome org>]

commit 06c64adb5762fb3f1691b0404a264063914f2bde
Author: Robert Bragg <robert linux intel com>
Date:   Tue May 3 21:00:00 2011 +0100

    Add missing _cogl_winsys_has_feature prototype
    
    This adds a private prototype for _cogl_winsys_has_feature in
    cogl-winsys-private.h to avoid compilation warnings.

 clutter/cogl/cogl/winsys/cogl-winsys-private.h |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/clutter/cogl/cogl/winsys/cogl-winsys-private.h b/clutter/cogl/cogl/winsys/cogl-winsys-private.h
index 856fc8d..e09fde9 100644
--- a/clutter/cogl/cogl/winsys/cogl-winsys-private.h
+++ b/clutter/cogl/cogl/winsys/cogl-winsys-private.h
@@ -144,4 +144,7 @@ typedef struct _CoglWinsysVtable
 
 } CoglWinsysVtable;
 
+gboolean
+_cogl_winsys_has_feature (CoglWinsysFeature feature);
+
 #endif /* __COGL_WINSYS_PRIVATE_H */