devPrivates rework: since API is already broken, switch everything

over to new system.

Need to update documentation and address some remaining vestiges of
old system such as CursorRec structure, fb "offman" structure, and
FontRec privates.

fb/fboverlay.h

@@ -25,9 +25,9 @@
 #ifndef _FBOVERLAY_H_
 #define _FBOVERLAY_H_
 
-extern int	fbOverlayGeneration;
-extern int	fbOverlayScreenPrivateIndex; /* XXX should be static */
-extern int	fbOverlayGetScreenPrivateIndex(void);
+#include "privates.h"
+
+extern DevPrivateKey fbOverlayGetScreenPrivateKey(void);
 
 #ifndef FB_OVERLAY_MAX
 #define FB_OVERLAY_MAX	2
@@ -58,8 +58,7 @@ typedef struct _fbOverlayScrPriv {
 } FbOverlayScrPrivRec, *FbOverlayScrPrivPtr;
 
 #define fbOverlayGetScrPriv(s) \
-    ((fbOverlayGetScreenPrivateIndex() != -1) ? \
-     (s)->devPrivates[fbOverlayGetScreenPrivateIndex()].ptr : NULL)
+    dixLookupPrivate(&(s)->devPrivates, fbOverlayGetScreenPrivateKey())
 Bool
 fbOverlayCreateWindow(WindowPtr pWin);