[mutter] boxes: Use G_DEFINE_BOXED_TYPE to define the type

[Marco Trevisan <marcotrevi src gnome org>]

commit 0aa4a526c63aeed1dc4d9f86e4db3d7072627344
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Tue May 14 14:09:30 2019 -0500

    boxes: Use G_DEFINE_BOXED_TYPE to define the type
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/581

 src/core/boxes.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)
---
diff --git a/src/core/boxes.c b/src/core/boxes.c
index 29cba5778..45efd8da2 100644
--- a/src/core/boxes.c
+++ b/src/core/boxes.c
@@ -55,17 +55,8 @@ meta_rectangle_free (MetaRectangle *rect)
   g_free (rect);
 }
 
-GType
-meta_rectangle_get_type (void)
-{
-  static GType type_id = 0;
-
-  if (!type_id)
-    type_id = g_boxed_type_register_static (g_intern_static_string ("MetaRectangle"),
-                                           (GBoxedCopyFunc) meta_rectangle_copy,
-                                           (GBoxedFreeFunc) meta_rectangle_free);
-  return type_id;
-}
+G_DEFINE_BOXED_TYPE (MetaRectangle, meta_rectangle,
+                     meta_rectangle_copy, meta_rectangle_free);
 
 char*
 meta_rectangle_to_string (const MetaRectangle *rect,