[Sync] Move //sync to //components/sync.

sync/tools/null_invalidation_state_tracker.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_TOOLS_NULL_INVALIDATION_STATE_TRACKER_H_
-#define SYNC_TOOLS_NULL_INVALIDATION_STATE_TRACKER_H_
-
-#include <string>
-
-#include "base/compiler_specific.h"
-#include "base/memory/weak_ptr.h"
-#include "components/invalidation/impl/invalidation_state_tracker.h"
-
-namespace syncer {
-
-class NullInvalidationStateTracker
-    : public base::SupportsWeakPtr<NullInvalidationStateTracker>,
-      public InvalidationStateTracker {
- public:
-  NullInvalidationStateTracker();
-  ~NullInvalidationStateTracker() override;
-
-  void ClearAndSetNewClientId(const std::string& data) override;
-  std::string GetInvalidatorClientId() const override;
-
-  std::string GetBootstrapData() const override;
-  void SetBootstrapData(const std::string& data) override;
-
-  void SetSavedInvalidations(const UnackedInvalidationsMap& states) override;
-  UnackedInvalidationsMap GetSavedInvalidations() const override;
-
-  void Clear() override;
-};
-
-}  // namespace syncer
-
-#endif  // SYNC_TOOLS_NULL_INVALIDATION_STATE_TRACKER_H_