[cogl] Set COGL_WINSYS_FEATURE_BUFFER_AGE on EGL

[Neil Roberts <nroberts src gnome org>]

commit 8418e98b2b1b25515a961ad1bb9f0c4770d6eb1d
Author: Neil Roberts <neil linux intel com>
Date:   Fri Mar 14 13:30:49 2014 +0000

    Set COGL_WINSYS_FEATURE_BUFFER_AGE on EGL
    
    This winsys feature flag is exposed via the deprecated
    cogl_clutter_winsys_has_feature function and Clutter is curently
    relying on it. Previously the EGL winsys was only setting the internal
    COGL_EGL_WINSYS_FEATURE_BUFFER_AGE flag and there was no mapping to
    the public flag. Therefore the feature would only be used on GLX. This
    patch just adds the mapping.
    
    Reviewed-by: Robert Bragg <robert linux intel com>

 cogl/winsys/cogl-winsys-egl.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/cogl/winsys/cogl-winsys-egl.c b/cogl/winsys/cogl-winsys-egl.c
index e336bfb..0bf5d7a 100644
--- a/cogl/winsys/cogl-winsys-egl.c
+++ b/cogl/winsys/cogl-winsys-egl.c
@@ -513,6 +513,11 @@ _cogl_winsys_context_init (CoglContext *context, CoglError **error)
       _cogl_has_private_feature (context, COGL_PRIVATE_FEATURE_OES_EGL_SYNC))
     COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_FENCE, TRUE);
 
+  if (egl_renderer->private_features & COGL_EGL_WINSYS_FEATURE_BUFFER_AGE)
+    COGL_FLAGS_SET (context->winsys_features,
+                    COGL_WINSYS_FEATURE_BUFFER_AGE,
+                    TRUE);
+
   /* NB: We currently only support creating standalone GLES2 contexts
    * for offscreen rendering and so we need a dummy (non-visible)
    * surface to be able to bind those contexts */