[mutter] backend: Remove unused barrier vfunc

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

commit 73bb3330002a10b51b17808d2e13aac10ac4e067
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Sep 1 23:00:31 2022 +0200

    backend: Remove unused barrier vfunc
    
    It was added in error, and has been unused since its introduction. Lets
    correct the error.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2604>

 src/backends/meta-backend-private.h | 6 ------
 src/backends/meta-backend.c         | 8 --------
 2 files changed, 14 deletions(-)
---
diff --git a/src/backends/meta-backend-private.h b/src/backends/meta-backend-private.h
index 21db6ca211..6053eb9421 100644
--- a/src/backends/meta-backend-private.h
+++ b/src/backends/meta-backend-private.h
@@ -107,9 +107,6 @@ struct _MetaBackendClass
   void (* update_screen_size) (MetaBackend *backend, int width, int height);
   void (* select_stage_events) (MetaBackend *backend);
 
-  MetaBarrierImpl * (* create_barrier_impl) (MetaBackend *backend,
-                                             MetaBarrier *barrier);
-
   void (* set_pointer_constraint) (MetaBackend           *backend,
                                    MetaPointerConstraint *constraint);
 
@@ -171,9 +168,6 @@ xkb_layout_index_t meta_backend_get_keymap_layout_group (MetaBackend *backend);
 
 gboolean meta_backend_is_lid_closed (MetaBackend *backend);
 
-MetaBarrierImpl * meta_backend_create_barrier_impl (MetaBackend *backend,
-                                                    MetaBarrier *barrier);
-
 MetaPointerConstraint * meta_backend_get_client_pointer_constraint (MetaBackend *backend);
 void meta_backend_set_client_pointer_constraint (MetaBackend *backend,
                                                  MetaPointerConstraint *constraint);
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index a24ed393f0..32d8834207 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -1589,14 +1589,6 @@ meta_backend_set_client_pointer_constraint (MetaBackend           *backend,
   g_set_object (&priv->client_pointer_constraint, constraint);
 }
 
-MetaBarrierImpl *
-meta_backend_create_barrier_impl (MetaBackend *backend,
-                                  MetaBarrier *barrier)
-{
-  return META_BACKEND_GET_CLASS (backend)->create_barrier_impl (backend,
-                                                                barrier);
-}
-
 ClutterBackend *
 meta_backend_get_clutter_backend (MetaBackend *backend)
 {