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

chrome/browser/extensions/settings/setting_sync_data.cc

 // Copyright (c) 2012 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/setting_sync_data.h"
 
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "chrome/browser/sync/api/sync_data.h"
 #include "chrome/browser/sync/protocol/app_setting_specifics.pb.h"
@@ skipping 10 matching lines @@
 SettingSyncData::SettingSyncData(
     const SyncData& sync_data) {
   Init(SyncChange::ACTION_INVALID, sync_data);
 }
 
 void SettingSyncData::Init(
     SyncChange::SyncChangeType change_type, const SyncData& sync_data) {
   DCHECK(!internal_.get());
   sync_pb::EntitySpecifics specifics = sync_data.GetSpecifics();
   // The data must only be either extension or app specfics.
-  DCHECK_NE(specifics.HasExtension(sync_pb::extension_setting),
-            specifics.HasExtension(sync_pb::app_setting));
-  if (specifics.HasExtension(sync_pb::extension_setting)) {
+  DCHECK_NE(specifics.has_extension_setting(),
+            specifics.has_app_setting());
+  if (specifics.has_extension_setting()) {
     InitFromExtensionSettingSpecifics(
         change_type,
-        specifics.GetExtension(sync_pb::extension_setting));
-  } else if (specifics.HasExtension(sync_pb::app_setting)) {
+        specifics.extension_setting());
+  } else if (specifics.has_app_setting()) {
     InitFromExtensionSettingSpecifics(
         change_type,
-        specifics.GetExtension(sync_pb::app_setting).extension_setting());
+        specifics.app_setting().extension_setting());
   }
 }
 
 void SettingSyncData::InitFromExtensionSettingSpecifics(
     SyncChange::SyncChangeType change_type,
     const sync_pb::ExtensionSettingSpecifics& specifics) {
   DCHECK(!internal_.get());
   scoped_ptr<Value> value(
       base::JSONReader().JsonToValue(specifics.value(), false, false));
   if (!value.get()) {
@@ skipping 41 matching lines @@
     : change_type_(change_type),
       extension_id_(extension_id),
       key_(key),
       value_(value.Pass()) {
   DCHECK(value_.get());
 }
 
 SettingSyncData::Internal::~Internal() {}
 
 }  // namespace extensions