[gtk+] widget: Annotate out params of _translate_coordinates as optional

[Timm Bäder <baedert src gnome org>]

commit 033c6c82d0172a18723e672ff1dae7b921726f93
Author: Timm Bäder <mail baedert org>
Date:   Sun Jan 31 00:01:31 2016 +0100

    widget: Annotate out params of _translate_coordinates as optional

 gtk/gtkwidget.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 2c9f776..7a05c56 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -6252,8 +6252,8 @@ gtk_widget_common_ancestor (GtkWidget *widget_a,
  * @dest_widget: a #GtkWidget
  * @src_x: X position relative to @src_widget
  * @src_y: Y position relative to @src_widget
- * @dest_x: (out): location to store X position relative to @dest_widget
- * @dest_y: (out): location to store Y position relative to @dest_widget
+ * @dest_x: (out) (optional): location to store X position relative to @dest_widget
+ * @dest_y: (out) (optional): location to store Y position relative to @dest_widget
  *
  * Translate coordinates relative to @src_widget’s allocation to coordinates
  * relative to @dest_widget’s allocations. In order to perform this