[glib] Revert "registrybackend: use G_DECLARE_FINAL_TYPE"

[Ignacio Casal Quinteiro <icq src gnome org>]

commit f3334b47ec6df3cd7eb1a0c7eafd15a4f21256f2
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Wed Feb 24 09:33:22 2016 +0100

    Revert "registrybackend: use G_DECLARE_FINAL_TYPE"
    
    This reverts commit b0776ddd1850f5ca91fe50c11311fe5c9c90cf53.
    mingw does not seem to like this patch so better go on the safe
    way.

 gio/gregistrysettingsbackend.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/gio/gregistrysettingsbackend.c b/gio/gregistrysettingsbackend.c
index 6cb995f..e35f48e 100644
--- a/gio/gregistrysettingsbackend.c
+++ b/gio/gregistrysettingsbackend.c
@@ -152,9 +152,15 @@ typedef struct
   HANDLE message_sent_event, message_received_event;
 } WatchThreadState;
 
-G_DECLARE_FINAL_TYPE (GRegistryBackend, g_registry_backend, G, REGISTRY_BACKEND, GSettingsBackend)
+#define G_TYPE_REGISTRY_BACKEND      (g_registry_backend_get_type ())
+#define G_REGISTRY_BACKEND(inst)     (G_TYPE_CHECK_INSTANCE_CAST ((inst),         \
+                                      G_TYPE_REGISTRY_BACKEND, GRegistryBackend))
+#define G_IS_REGISTRY_BACKEND(inst)  (G_TYPE_CHECK_INSTANCE_TYPE ((inst),         \
+                                      G_TYPE_REGISTRY_BACKEND))
 
-struct _GRegistryBackend {
+typedef GSettingsBackendClass GRegistryBackendClass;
+
+typedef struct {
   GSettingsBackend parent_instance;
 
   gchar *base_path;
@@ -166,7 +172,7 @@ struct _GRegistryBackend {
   GNode *cache_root;
 
   WatchThreadState *watch;
-};
+} GRegistryBackend;
 
 G_DEFINE_TYPE_WITH_CODE (GRegistryBackend,
                          g_registry_backend,