Make GCMDriver::GetInstanceIDHandler protected, to avoid misuse

components/gcm_driver/instance_id/instance_id_impl.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 COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_IMPL_H_
 #define COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_IMPL_H_
 
 #include <map>
 #include <string>
 
@@ skipping 25 matching lines @@
   void GetToken(const std::string& authorized_entity,
                 const std::string& scope,
                 const std::map<std::string, std::string>& options,
                 const GetTokenCallback& callback) override;
   void DeleteToken(const std::string& authorized_entity,
                    const std::string& scope,
                    const DeleteTokenCallback& callback) override;
   void DeleteID(const DeleteIDCallback& callback) override;
 
  private:
-  gcm::InstanceIDHandler* GetInstanceIDHandler() const;
-
   void EnsureIDGenerated();
 
   void OnGetTokenCompleted(const GetTokenCallback& callback,
                            const std::string& token,
                            gcm::GCMClient::Result result);
   void OnDeleteTokenCompleted(const DeleteTokenCallback& callback,
                               gcm::GCMClient::Result result);
   void OnDeleteIDCompleted(const DeleteIDCallback& callback,
                            gcm::GCMClient::Result result);
   void GetInstanceIDDataCompleted(const std::string& instance_id,
                                   const std::string& extra_data);
 
   void DoGetID(const GetIDCallback& callback);
   void DoGetCreationTime(const GetCreationTimeCallback& callback);
   void DoGetToken(
       const std::string& authorized_entity,
       const std::string& scope,
       const std::map<std::string, std::string>& options,
       const GetTokenCallback& callback);
   void DoDeleteToken(const std::string& authorized_entity,
                      const std::string& scope,
                      const DeleteTokenCallback& callback);
   void DoDeleteID(const DeleteIDCallback& callback);
 
-  gcm::GCMDriver* gcm_driver_;  // Not owned.
-
   gcm::GCMDelayedTaskController delayed_task_controller_;
 
   // The generated Instance ID.
   std::string id_;
 
   // The time when the Instance ID has been generated.
   base::Time creation_time_;
 
   base::WeakPtrFactory<InstanceIDImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceIDImpl);
 };
 
 }  // namespace instance_id
 
 #endif  // COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_IMPL_H_