Implement new invalidations ack tracking system

sync/notifier/fake_invalidator.h

Index: sync/notifier/fake_invalidator.h
diff --git a/sync/notifier/fake_invalidator.h b/sync/notifier/fake_invalidator.h
index 7913694254e09eadb67f45c83e468a6ff6cf4599..b2173eef4ac0355c853e8ffceb179db27b967ae8 100644
--- a/sync/notifier/fake_invalidator.h
+++ b/sync/notifier/fake_invalidator.h
@@ -24,7 +24,6 @@ class FakeInvalidator : public Invalidator {
   const std::string& GetUniqueId() const;
   const std::string& GetCredentialsEmail() const;
   const std::string& GetCredentialsToken() const;
-  const ObjectIdInvalidationMap& GetLastSentInvalidationMap() const;
 
   void EmitOnInvalidatorStateChange(InvalidatorState state);
   void EmitOnIncomingInvalidation(
@@ -34,8 +33,6 @@ class FakeInvalidator : public Invalidator {
   virtual void UpdateRegisteredIds(InvalidationHandler* handler,
                                    const ObjectIdSet& ids) OVERRIDE;
   virtual void UnregisterHandler(InvalidationHandler* handler) OVERRIDE;
-  virtual void Acknowledge(const invalidation::ObjectId& id,
-                           const AckHandle& ack_handle) OVERRIDE;
   virtual InvalidatorState GetInvalidatorState() const OVERRIDE;
   virtual void UpdateCredentials(
       const std::string& email, const std::string& token) OVERRIDE;