[Sync] Moving DataTypeState to proto for serialization

sync/internal_api/public/activation_context.h

 // Copyright 2015 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_INTERNAL_API_PUBLIC_ACTIVATION_CONTEXT_H_
 #define SYNC_INTERNAL_API_PUBLIC_ACTIVATION_CONTEXT_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/model_type_processor.h"
 #include "sync/internal_api/public/non_blocking_sync_common.h"
+#include "sync/protocol/data_type_state.pb.h"
 
 namespace syncer_v2 {
 
 // The state passed from ModelTypeProcessor to Sync thread during DataType
 // activation.
 struct SYNC_EXPORT ActivationContext {
   ActivationContext();
   ~ActivationContext();
 
   // Initial DataTypeState at the moment of activation.
-  DataTypeState data_type_state;
+  sync_pb::DataTypeState data_type_state;
 
   // Pending updates from the previous session.
   // TODO(stanisc): crbug.com/529498: should remove pending updates.
   UpdateResponseDataList saved_pending_updates;
 
   // The ModelTypeProcessor for the worker. Note that this is owned because
   // it is generally a proxy object to the real processor.
   scoped_ptr<ModelTypeProcessor> type_processor;
 };
 
 }  // namespace syncer_v2
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_ACTIVATION_CONTEXT_H_