Delete old client info migration behavior.

components/metrics/metrics_state_manager.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_METRICS_METRICS_STATE_MANAGER_H_
 #define COMPONENTS_METRICS_METRICS_STATE_MANAGER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 100 matching lines @@
   // |store_client_info| should back up client info to persistent storage such
   // that it is later retrievable by |load_client_info|.
   MetricsStateManager(PrefService* local_state,
                       EnabledStateProvider* enabled_state_provider,
                       const StoreClientInfoCallback& store_client_info,
                       const LoadClientInfoCallback& load_client_info);
 
   // Backs up the current client info via |store_client_info_|.
   void BackUpCurrentClientInfo();
 
-  // Loads the client info via |load_client_info_| and potentially migrates it
-  // before returning it if it comes back in its old form.
-  std::unique_ptr<ClientInfo> LoadClientInfoAndMaybeMigrate();
+  // Loads the client info via |load_client_info_|.
+  std::unique_ptr<ClientInfo> LoadClientInfo();
 
   // Returns the low entropy source for this client. This is a random value
   // that is non-identifying amongst browser clients. This method will
   // generate the entropy source value if it has not been called before.
   int GetLowEntropySource();
 
   // Generates the low entropy source value for this client if it is not
   // already set.
   void UpdateLowEntropySource();
 
@@ skipping 41 matching lines @@
   EntropySourceType entropy_source_returned_;
 
   std::unique_ptr<ClonedInstallDetector> cloned_install_detector_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsStateManager);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_METRICS_STATE_MANAGER_H_