Implement new invalidations ack tracking system

sync/notifier/fake_invalidation_handler.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SYNC_NOTIFIER_FAKE_SYNC_NOTIFIER_OBSERVER_H_
 #define SYNC_NOTIFIER_FAKE_SYNC_NOTIFIER_OBSERVER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "sync/notifier/invalidation_handler.h"
+#include "sync/notifier/object_id_invalidation_map.h"
 
 namespace syncer {
 
 class FakeInvalidationHandler : public InvalidationHandler {
  public:
   FakeInvalidationHandler();
   virtual ~FakeInvalidationHandler();
 
   InvalidatorState GetInvalidatorState() const;
   const ObjectIdInvalidationMap& GetLastInvalidationMap() const;
   int GetInvalidationCount() const;
 
   // InvalidationHandler implementation.
   virtual void OnInvalidatorStateChange(InvalidatorState state) OVERRIDE;
   virtual void OnIncomingInvalidation(
       const ObjectIdInvalidationMap& invalidation_map) OVERRIDE;
 
  private:
   InvalidatorState state_;
   ObjectIdInvalidationMap last_invalidation_map_;
   int invalidation_count_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeInvalidationHandler);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_NOTIFIER_FAKE_SYNC_NOTIFIER_OBSERVER_H_