Implement new invalidations ack tracking system

sync/notifier/mock_ack_handler.h

 // Copyright 2013 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_MOCK_ACK_HANDLER_H_
 #define SYNC_NOTIFIER_MOCK_ACK_HANDLER_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/util/weak_handle.h"
 #include "sync/notifier/ack_handler.h"
 
 namespace syncer {
 
 class Invalidation;
 
 // This AckHandler implementation colaborates with the FakeInvalidationService
 // to enable unit tests to assert that invalidations are being acked properly.
-class MockAckHandler
+class SYNC_EXPORT MockAckHandler
   : public AckHandler,
     public base::SupportsWeakPtr<MockAckHandler> {
  public:
   MockAckHandler();
   virtual ~MockAckHandler();
 
   // Sets up some internal state to track this invalidation, and modifies it so
   // that its Acknowledge() and Drop() methods will route back to us.
   void RegisterInvalidation(Invalidation* invalidation);
 
@@ skipping 22 matching lines @@
   WeakHandle<AckHandler> WeakHandleThis();
 
   InvalidationVector unsent_invalidations_;
   InvalidationVector unacked_invalidations_;
   InvalidationVector acked_invalidations_;
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_NOTIFIER_MOCK_ACK_HANDLER_H_