Convert JsonWriter::Write to taking a const ref for the in-param

chrome/browser/supervised_user/legacy/supervised_user_shared_settings_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 "chrome/browser/supervised_user/legacy/supervised_user_shared_settings_service.h"
 
 #include <map>
 #include <set>
 
 #include "base/json/json_reader.h"
@@ skipping 156 matching lines @@
   registry->RegisterDictionaryPref(prefs::kSupervisedUserSharedSettings);
 }
 
 // static
 SyncData SupervisedUserSharedSettingsService::CreateSyncDataForSetting(
     const std::string& su_id,
     const std::string& key,
     const Value& value,
     bool acknowledged) {
   std::string json_value;
-  base::JSONWriter::Write(&value, &json_value);
+  base::JSONWriter::Write(value, &json_value);
   ::sync_pb::EntitySpecifics specifics;
   specifics.mutable_managed_user_shared_setting()->set_mu_id(su_id);
   specifics.mutable_managed_user_shared_setting()->set_key(key);
   specifics.mutable_managed_user_shared_setting()->set_value(json_value);
   specifics.mutable_managed_user_shared_setting()->set_acknowledged(
       acknowledged);
   std::string title = su_id + ":" + key;
   return SyncData::CreateLocalData(title, title, specifics);
 }
 
@@ skipping 148 matching lines @@
         NOTREACHED();
         break;
       }
     }
     callbacks_.Notify(su_id, key);
   }
 
   SyncError error;
   return error;
 }