[evolution-data-server] ECollectionBackendClass: Add dup_resource_id() method.

[Matthew Barnes <mbarnes src gnome org>]

commit 3992f5cdd0e6661cc374adf563ce813622d64a6a
Author: Matthew Barnes <mbarnes redhat com>
Date:   Mon Jun 11 14:45:53 2012 -0400

    ECollectionBackendClass: Add dup_resource_id() method.
    
    Returns the resource ID for a given child source.  A resource ID is
    usually a unique, server-assigned identifier which is stored in the
    child source in some backend-specific extension.  The method allows
    ECollectionBackend to extract the ID without knowing exactly how it
    is stored.  The method always returns a newly-allocated string.

 libebackend/e-collection-backend.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/libebackend/e-collection-backend.h b/libebackend/e-collection-backend.h
index 6670480..3b97922 100644
--- a/libebackend/e-collection-backend.h
+++ b/libebackend/e-collection-backend.h
@@ -70,6 +70,8 @@ struct _ECollectionBackendClass {
 
 	/* Methods */
 	void		(*populate)		(ECollectionBackend *backend);
+	gchar *		(*dup_resource_id)	(ECollectionBackend *backend,
+						 ESource *child_source);
 
 	/* Signals */
 	void		(*child_added)		(ECollectionBackend *backend,