Introduce PrefRegistrySyncable, simplifying PrefServiceSyncable.

chrome/browser/profiles/chrome_version_service.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/profiles/chrome_version_service.h"
 
 #include "base/version.h"
+#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/pref_names.h"
 
 // static
-void ChromeVersionService::RegisterUserPrefs(PrefServiceSyncable* prefs) {
-  prefs->RegisterStringPref(prefs::kProfileCreatedByVersion, "1.0.0.0",
-      PrefServiceSyncable::UNSYNCABLE_PREF);
+void ChromeVersionService::RegisterUserPrefs(PrefRegistrySyncable* registry) {
+  registry->RegisterStringPref(prefs::kProfileCreatedByVersion,
+                               "1.0.0.0",
+                               PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 // static
 void ChromeVersionService::SetVersion(PrefService* prefs,
                                       const std::string& version) {
   prefs->SetString(prefs::kProfileCreatedByVersion, version);
 }
 
 // static
 std::string ChromeVersionService::GetVersion(PrefService* prefs) {
   return prefs->GetString(prefs::kProfileCreatedByVersion);
 }
 
 // static
 void ChromeVersionService::OnProfileLoaded(PrefService* prefs,
                                            bool is_new_profile) {
   // Obtain the Chrome version info.
   chrome::VersionInfo version_info;
 
   // If this is a new profile set version to current version, otherwise
   // (pre-existing profile), leave pref at default value (1.0.0.0) to
   // avoid any first-run behavior.
   std::string version = version_info.Version();
   if (prefs->FindPreference(prefs::kProfileCreatedByVersion)->
       IsDefaultValue() && is_new_profile) {
     SetVersion(prefs, version);
   }
 }