[gnome-builder] back-forward-list: add source tag for debugging

[Christian Hergert <chergert src gnome org>]

commit 875f04daccd7a9b19eff4133797a272fe4f7229f
Author: Christian Hergert <chergert redhat com>
Date:   Mon Mar 6 18:06:29 2017 -0800

    back-forward-list: add source tag for debugging

 libide/history/ide-back-forward-list-save.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/libide/history/ide-back-forward-list-save.c b/libide/history/ide-back-forward-list-save.c
index 5038143..17bc391 100644
--- a/libide/history/ide-back-forward-list-save.c
+++ b/libide/history/ide-back-forward-list-save.c
@@ -169,6 +169,7 @@ _ide_back_forward_list_save_async (IdeBackForwardList  *self,
   _ide_back_forward_list_foreach (self, ide_back_forward_list_save_collect, state);
 
   task = g_task_new (self, cancellable, callback, user_data);
+  g_task_set_source_tag (task, _ide_back_forward_list_save_async);
   g_task_set_task_data (task, state, ide_back_forward_list_save_free);
 
   if (state->content->len == 0)