Implement new invalidations ack tracking system

chrome/browser/invalidation/invalidation_service.h

Index: chrome/browser/invalidation/invalidation_service.h
diff --git a/chrome/browser/invalidation/invalidation_service.h b/chrome/browser/invalidation/invalidation_service.h
index 7ee0b73e0f61417ac256e199b1ebaff076aa4cb9..33b09f38e77cacc08c6e5b04328bd788fca879f7 100644
--- a/chrome/browser/invalidation/invalidation_service.h
+++ b/chrome/browser/invalidation/invalidation_service.h
@@ -11,7 +11,6 @@
 
 namespace syncer {
 class InvalidationHandler;
-class AckHandle;
 }  // namespace syncer
 
 namespace invalidation {
@@ -91,11 +90,6 @@ class InvalidationService : public BrowserContextKeyedService {
   virtual void UnregisterInvalidationHandler(
       syncer::InvalidationHandler* handler) = 0;
 
-  // Sends an acknowledgement that an invalidation for |id| was successfully
-  // handled.
-  virtual void AcknowledgeInvalidation(const invalidation::ObjectId& id,
-                                       const syncer::AckHandle& ack_handle) = 0;
-
   // Returns the current invalidator state.  When called from within
   // InvalidationHandler::OnInvalidatorStateChange(), this must return
   // the updated state.