Use std::unique_ptr for base::DictionaryValue and base::ListValue's internal store.

components/signin/core/browser/account_tracker_service.cc

 // 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.
 
 #include "components/signin/core/browser/account_tracker_service.h"
 
 #include <stddef.h>
 
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 330 matching lines @@
           state.info.locale = base::UTF16ToUTF8(value);
         if (dict->GetString(kAccountPictureURLPath, &value))
           state.info.picture_url = base::UTF16ToUTF8(value);
 
         bool is_child_account = false;
         // Migrate deprecated service flag preference.
         const base::ListValue* service_flags_list;
         if (dict->GetList(kAccountServiceFlagsPath, &service_flags_list)) {
           contains_deprecated_service_flags = true;
           std::string flag_string;
-          for (base::Value* flag : *service_flags_list) {
+          for (const auto& flag : *service_flags_list) {
             if (flag->GetAsString(&flag_string) &&
                 flag_string == kChildAccountServiceFlag) {
               is_child_account = true;
               break;
             }
           }
           state.info.is_child_account = is_child_account;
         }
         if (dict->GetBoolean(kAccountChildAccountStatusPath, &is_child_account))
           state.info.is_child_account = is_child_account;
@@ skipping 139 matching lines @@
       NotifyAccountUpdated(state);
     }
     SaveToPrefs(state);
   }
   return info.account_id;
 }
 
 void AccountTrackerService::RemoveAccount(const std::string& account_id) {
   StopTrackingAccount(account_id);
 }