[grilo] Update gtk-doc

[Juan A. Suarez Romero <jasuarez src gnome org>]

commit 7088acd9e63105c66a3b560f07907b4de67be3a0
Author: Juan A. Suarez Romero <jasuarez igalia com>
Date:   Tue Jun 15 16:59:13 2010 +0200

    Update gtk-doc
    
    grl_metadata_source_key_depends() returns NULL if source is not able to resolve
    the key.

 src/grl-metadata-source.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/grl-metadata-source.c b/src/grl-metadata-source.c
index 51d2d3f..c32d0c6 100644
--- a/src/grl-metadata-source.c
+++ b/src/grl-metadata-source.c
@@ -502,7 +502,8 @@ grl_metadata_source_slow_keys (GrlMetadataSource *source)
  * Get the list of #GrlKeyID which are needed a priori, in order to fetch
  * and store the requested @key_id
  *
- * Returns: (transfer none) (allow-none): a #GList with the keys
+ * Returns: (transfer none) (allow-none): a #GList with the keys, or @NULL if it
+ * can not resolve @key_id
  */
 const GList *
 grl_metadata_source_key_depends (GrlMetadataSource *source, GrlKeyID key_id)