Remove GdkSeatGrabPrepareFunc from headers

It is not used in public api anymore.

gdk/gdkinternals.h

@@ -255,6 +255,21 @@ void gdk_surface_get_geometry (GdkSurface *surface,
 
 GdkGLContext *gdk_surface_get_shared_data_gl_context (GdkSurface *surface);
 
+/*
+ * GdkSeatGrabPrepareFunc:
+ * @seat: the #GdkSeat being grabbed
+ * @surface: the #GdkSurface being grabbed
+ * @user_data: user data passed in gdk_seat_grab()
+ *
+ * Type of the callback used to set up @surface so it can be
+ * grabbed. A typical action would be ensuring the surface is
+ * visible, although there's room for other initialization
+ * actions.
+ */
+typedef void (* GdkSeatGrabPrepareFunc) (GdkSeat   *seat,
+                                         GdkSurface *surface,
+                                         gpointer   user_data);
+
 GdkGrabStatus  gdk_seat_grab             (GdkSeat                *seat,
                                           GdkSurface              *surface,
                                           GdkSeatCapabilities     capabilities,

gdk/gdkseat.h

@@ -59,21 +59,6 @@ typedef enum {
   GDK_SEAT_CAPABILITY_ALL           = (GDK_SEAT_CAPABILITY_ALL_POINTING | GDK_SEAT_CAPABILITY_KEYBOARD)
 } GdkSeatCapabilities;
 
-/**
- * GdkSeatGrabPrepareFunc:
- * @seat: the #GdkSeat being grabbed
- * @surface: the #GdkSurface being grabbed
- * @user_data: user data passed in gdk_seat_grab()
- *
- * Type of the callback used to set up @surface so it can be
- * grabbed. A typical action would be ensuring the surface is
- * visible, although there's room for other initialization
- * actions.
- */
-typedef void (* GdkSeatGrabPrepareFunc) (GdkSeat   *seat,
-                                         GdkSurface *surface,
-                                         gpointer   user_data);
-
 struct _GdkSeat
 {
   GObject parent_instance;

gdk/gdkseatprivate.h

@@ -23,6 +23,7 @@
 typedef struct _GdkSeatClass GdkSeatClass;
 
 #include "gdkseat.h"
+#include "gdkinternals.h"
 
 #define GDK_SEAT_CLASS(c)     (G_TYPE_CHECK_CLASS_CAST ((c), GDK_TYPE_SEAT, GdkSeatClass))
 #define GDK_IS_SEAT_CLASS(c)  (G_TYPE_CHECK_CLASS_TYPE ((c), GDK_TYPE_SEAT))