Introduce a layering in the invalidation component as public and impl

components/invalidation/fake_invalidator.h

Index: components/invalidation/fake_invalidator.h
diff --git a/components/invalidation/fake_invalidator.h b/components/invalidation/fake_invalidator.h
deleted file mode 100644
index 2d24361b2716794595c18226e403e28914ada33e..0000000000000000000000000000000000000000
--- a/components/invalidation/fake_invalidator.h
+++ /dev/null
@@ -1,52 +0,0 @@
-// Copyright 2014 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 COMPONENTS_INVALIDATION_FAKE_INVALIDATOR_H_
-#define COMPONENTS_INVALIDATION_FAKE_INVALIDATOR_H_
-
-#include <string>
-
-#include "base/callback_forward.h"
-#include "base/compiler_specific.h"
-#include "components/invalidation/invalidation_util.h"
-#include "components/invalidation/invalidator.h"
-#include "components/invalidation/invalidator_registrar.h"
-
-namespace syncer {
-
-class FakeInvalidator : public Invalidator {
- public:
-  FakeInvalidator();
-  ~FakeInvalidator() override;
-
-  bool IsHandlerRegistered(InvalidationHandler* handler) const;
-  ObjectIdSet GetRegisteredIds(InvalidationHandler* handler) const;
-  const std::string& GetUniqueId() const;
-  const std::string& GetCredentialsEmail() const;
-  const std::string& GetCredentialsToken() const;
-
-  void EmitOnInvalidatorStateChange(InvalidatorState state);
-  void EmitOnIncomingInvalidation(
-      const ObjectIdInvalidationMap& invalidation_map);
-
-  void RegisterHandler(InvalidationHandler* handler) override;
-  bool UpdateRegisteredIds(InvalidationHandler* handler,
-                           const ObjectIdSet& ids) override;
-  void UnregisterHandler(InvalidationHandler* handler) override;
-  InvalidatorState GetInvalidatorState() const override;
-  void UpdateCredentials(const std::string& email,
-                         const std::string& token) override;
-  void RequestDetailedStatus(base::Callback<void(const base::DictionaryValue&)>
-                                 callback) const override;
-
- private:
-  InvalidatorRegistrar registrar_;
-  std::string state_;
-  std::string email_;
-  std::string token_;
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_INVALIDATION_FAKE_INVALIDATOR_H_