Make GCMDriver::GetInstanceIDHandler protected, to avoid misuse

components/gcm_driver/fake_gcm_driver.h

 // 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_GCM_DRIVER_FAKE_GCM_DRIVER_H_
 #define COMPONENTS_GCM_DRIVER_FAKE_GCM_DRIVER_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "components/gcm_driver/gcm_driver.h"
@@ skipping 22 matching lines @@
                         ClearActivityLogs clear_logs) override;
   void SetGCMRecording(const GetGCMStatisticsCallback& callback,
                        bool recording) override;
   void SetAccountTokens(
       const std::vector<GCMClient::AccountTokenInfo>& account_tokens) override;
   void UpdateAccountMapping(const AccountMapping& account_mapping) override;
   void RemoveAccountMapping(const std::string& account_id) override;
   base::Time GetLastTokenFetchTime() override;
   void SetLastTokenFetchTime(const base::Time& time) override;
   void WakeFromSuspendForHeartbeat(bool wake) override;
-  InstanceIDHandler* GetInstanceIDHandler() override;
+  InstanceIDHandler* GetInstanceIDHandlerInternal() override;
   void AddHeartbeatInterval(const std::string& scope, int interval_ms) override;
   void RemoveHeartbeatInterval(const std::string& scope) override;
 
  protected:
   // GCMDriver implementation:
   GCMClient::Result EnsureStarted(
       GCMClient::StartMode start_mode) override;
   void RegisterImpl(const std::string& app_id,
                     const std::vector<std::string>& sender_ids) override;
   void UnregisterImpl(const std::string& app_id) override;
   void SendImpl(const std::string& app_id,
                 const std::string& receiver_id,
                 const OutgoingMessage& message) override;
   void RecordDecryptionFailure(const std::string& app_id,
                                GCMEncryptionProvider::DecryptionResult result)
       override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FakeGCMDriver);
 };
 
 }  // namespace gcm
 
 #endif  // COMPONENTS_GCM_DRIVER_FAKE_GCM_DRIVER_H_