sync: remove use of protobuf extensions in protocol to reduce static init overhead.

chrome/browser/extensions/settings/settings_sync_util.cc

 // Copyright (c) 2011 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/extensions/settings/settings_sync_util.h"
 
 #include "base/values.h"
 #include "base/json/json_writer.h"
 #include "chrome/browser/sync/protocol/extension_setting_specifics.pb.h"
+#include "chrome/browser/sync/protocol/sync.pb.h"
 
 namespace extensions {
 
 namespace settings_sync_util {
 
 SyncData CreateData(
     const std::string& extension_id,
     const std::string& key,
     const Value& value) {
   sync_pb::EntitySpecifics specifics;
   sync_pb::ExtensionSettingSpecifics* setting_specifics =
-      specifics.MutableExtension(sync_pb::extension_setting);
+      specifics.mutable_extension_setting();
   setting_specifics->set_extension_id(extension_id);
   setting_specifics->set_key(key);
   std::string value_as_json;
   base::JSONWriter::Write(&value, false, &value_as_json);
   setting_specifics->set_value(value_as_json);
   return SyncData::CreateLocalData(extension_id + "/" + key, key, specifics);
 }
 
 SyncChange CreateAdd(
     const std::string& extension_id,
@@ skipping 14 matching lines @@
 SyncChange CreateDelete(
     const std::string& extension_id, const std::string& key) {
   DictionaryValue no_value;
   return SyncChange(
       SyncChange::ACTION_DELETE, CreateData(extension_id, key, no_value));
 }
 
 }  // namespace settings_sync_util
 
 }  // namespace extensions