[gtk+] docs: Add Since for GtkCellRendererPixbuf:surface

[David King <davidk src gnome org>]

commit a7638d5ecbcd08783320cb76653fbfe50bf5cd02
Author: David King <dking redhat com>
Date:   Fri Jan 9 14:37:17 2015 +0000

    docs: Add Since for GtkCellRendererPixbuf:surface

 gtk/gtkcellrendererpixbuf.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkcellrendererpixbuf.c b/gtk/gtkcellrendererpixbuf.c
index 15e4a0d..54acb1a 100644
--- a/gtk/gtkcellrendererpixbuf.c
+++ b/gtk/gtkcellrendererpixbuf.c
@@ -168,6 +168,11 @@ gtk_cell_renderer_pixbuf_class_init (GtkCellRendererPixbufClass *class)
                                                        P_("Pixbuf for closed expander"),
                                                        GDK_TYPE_PIXBUF,
                                                        GTK_PARAM_READWRITE));
+  /**
+   * GtkCellRendererPixbuf:surface:
+   *
+   * Since: 3.10
+   */
   g_object_class_install_property (object_class,
                                   PROP_SURFACE,
                                   g_param_spec_boxed ("surface",