[orca] Don't bother processing active-descendant-changed events for zombie descendant

[Joanmarie Diggs <joanied src gnome org>]

commit 27a8f48bed96ce085508b3bf758a6362469ae709
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Fri Nov 20 17:17:56 2015 -0500

    Don't bother processing active-descendant-changed events for zombie descendant

 src/orca/event_manager.py |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/orca/event_manager.py b/src/orca/event_manager.py
index d5ce114..b1a5e1a 100644
--- a/src/orca/event_manager.py
+++ b/src/orca/event_manager.py
@@ -170,7 +170,8 @@ class EventManager:
                 debug.println(debug.LEVEL_INFO, msg)
                 return True
 
-        if event.type.startswith('object:children-changed:add'):
+        if event.type.startswith('object:children-changed:add') \
+           or event.type.startswith('object:active-descendant-changed'):
             if not event.any_data:
                 msg = 'ERROR: %s without child from source %s in app %s' % \
                       (event.type, event.source, event.host_application)