[mutter] wayland: Add MetaWaylandGtkShell object

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 00619f3a1cd0dbd7673a6e75da2351e90b419211
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Aug 23 15:53:55 2018 +0200

    wayland: Add MetaWaylandGtkShell object
    
    To be used to store state.
    
    https://gitlab.gnome.org/GNOME/mutter/issues/276

 src/wayland/meta-wayland-gtk-shell.c | 36 +++++++++++++++++++++++++++++++++---
 src/wayland/meta-wayland-gtk-shell.h |  6 +++++-
 src/wayland/meta-wayland-surface.c   |  2 +-
 3 files changed, 39 insertions(+), 5 deletions(-)
---
diff --git a/src/wayland/meta-wayland-gtk-shell.c b/src/wayland/meta-wayland-gtk-shell.c
index e050b89f9..6f88b2621 100644
--- a/src/wayland/meta-wayland-gtk-shell.c
+++ b/src/wayland/meta-wayland-gtk-shell.c
@@ -43,6 +43,13 @@ typedef struct _MetaWaylandGtkSurface
   gulong configure_handler_id;
 } MetaWaylandGtkSurface;
 
+struct _MetaWaylandGtkShell
+{
+  GObject parent;
+};
+
+G_DEFINE_TYPE (MetaWaylandGtkShell, meta_wayland_gtk_shell, G_TYPE_OBJECT)
+
 static void
 gtk_surface_destructor (struct wl_resource *resource)
 {
@@ -375,15 +382,38 @@ bind_gtk_shell (struct wl_client *client,
   gtk_shell1_send_capabilities (resource, capabilities);
 }
 
-void
-meta_wayland_gtk_shell_init (MetaWaylandCompositor *compositor)
+static void
+meta_wayland_gtk_shell_init (MetaWaylandGtkShell *gtk_shell)
+{
+}
+
+static void
+meta_wayland_gtk_shell_class_init (MetaWaylandGtkShellClass *klass)
 {
   quark_gtk_surface_data =
     g_quark_from_static_string ("-meta-wayland-gtk-shell-surface-data");
+}
+
+static MetaWaylandGtkShell *
+meta_wayland_gtk_shell_new (MetaWaylandCompositor *compositor)
+{
+  MetaWaylandGtkShell *gtk_shell;
+
+  gtk_shell = g_object_new (META_TYPE_WAYLAND_GTK_SHELL, NULL);
 
   if (wl_global_create (compositor->wayland_display,
                         &gtk_shell1_interface,
                         META_GTK_SHELL1_VERSION,
-                        compositor, bind_gtk_shell) == NULL)
+                        gtk_shell, bind_gtk_shell) == NULL)
     g_error ("Failed to register a global gtk-shell object");
+
+  return gtk_shell;
+}
+
+void
+meta_wayland_init_gtk_shell (MetaWaylandCompositor *compositor)
+{
+  g_object_set_data_full (G_OBJECT (compositor), "-meta-wayland-gtk-shell",
+                          meta_wayland_gtk_shell_new (compositor),
+                          g_object_unref);
 }
diff --git a/src/wayland/meta-wayland-gtk-shell.h b/src/wayland/meta-wayland-gtk-shell.h
index 888ee40cc..347c1f398 100644
--- a/src/wayland/meta-wayland-gtk-shell.h
+++ b/src/wayland/meta-wayland-gtk-shell.h
@@ -22,6 +22,10 @@
 
 #include "wayland/meta-wayland.h"
 
-void meta_wayland_gtk_shell_init (MetaWaylandCompositor *compositor);
+#define META_TYPE_WAYLAND_GTK_SHELL (meta_wayland_gtk_shell_get_type ())
+G_DECLARE_FINAL_TYPE (MetaWaylandGtkShell, meta_wayland_gtk_shell,
+                      META, WAYLAND_GTK_SHELL, GObject)
+
+void meta_wayland_init_gtk_shell (MetaWaylandCompositor *compositor);
 
 #endif /* META_WAYLAND_GTK_SHELL_H */
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index b918e296e..8e12a7bb9 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -1284,7 +1284,7 @@ meta_wayland_shell_init (MetaWaylandCompositor *compositor)
   meta_wayland_xdg_shell_init (compositor);
   meta_wayland_legacy_xdg_shell_init (compositor);
   meta_wayland_wl_shell_init (compositor);
-  meta_wayland_gtk_shell_init (compositor);
+  meta_wayland_init_gtk_shell (compositor);
 }
 
 void