Implement new invalidations ack tracking system

chrome/browser/drive/drive_notification_manager.cc

Index: chrome/browser/drive/drive_notification_manager.cc
diff --git a/chrome/browser/drive/drive_notification_manager.cc b/chrome/browser/drive/drive_notification_manager.cc
index d4141b0a83ea552701c9e38ce864509662481564..f26c6c73fa40007b04670cdf94f93b22d6593088 100644
--- a/chrome/browser/drive/drive_notification_manager.cc
+++ b/chrome/browser/drive/drive_notification_manager.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/invalidation/invalidation_service.h"
 #include "chrome/browser/invalidation/invalidation_service_factory.h"
 #include "google/cacheinvalidation/types.pb.h"
+#include "sync/notifier/object_id_invalidation_map.h"
 
 namespace drive {
 
@@ -75,12 +76,8 @@ void DriveNotificationManager::OnIncomingInvalidation(
       kDriveInvalidationObjectId);
   DCHECK_EQ(1U, ids.count(object_id));
 
-  // TODO(dcheng): Only acknowledge the invalidation once the fetch has
-  // completed. http://crbug.com/156843
-  DCHECK(invalidation_service_);
-  syncer::Invalidation inv = invalidation_map.ForObject(object_id).back();
-  invalidation_service_->AcknowledgeInvalidation(object_id, inv.ack_handle());
-
+  // TODO: Acknowledge only after fetch completes.  See crbug.com/320878.

[satorux1, 2013/11/25 01:57:46]

nit: TODO should have a name.

[rlarocque, 2013/11/25 19:34:24]

Can you suggest an owner?

Implementing this would require intimate knowledge of the
DriveNotificationManager.  I don't think I'm qualified for the task.

I was just carrying over the old TODO without much thought.  Now that I think
about it, maybe this should be rephrased as "investigate if supporting
invalidations local acknowledgements is worthwhile", or removed entirely.  If
the current invalidations behavior suits your needs, then I guess there's no
need to spend much effort on improving its reliability.

+  invalidation_map.AcknowledgeAll();
   NotifyObserversToUpdate(NOTIFICATION_XMPP);
 }