Introduce PrefRegistrySyncable, simplifying PrefServiceSyncable.

chrome/browser/managed_mode/managed_user_service.cc

Index: chrome/browser/managed_mode/managed_user_service.cc
diff --git a/chrome/browser/managed_mode/managed_user_service.cc b/chrome/browser/managed_mode/managed_user_service.cc
index 8fbc39a4c301063635e27ee5577a142d26fb80a7..5dc1e7799793bdbdd0cd950ee590cdab3279b3f1 100644
--- a/chrome/browser/managed_mode/managed_user_service.cc
+++ b/chrome/browser/managed_mode/managed_user_service.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/managed_mode/managed_mode_site_list.h"
+#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/profiles/profile.h"
@@ -106,14 +107,14 @@ bool ManagedUserService::ProfileIsManaged() const {
 }
 
 // static
-void ManagedUserService::RegisterUserPrefs(PrefServiceSyncable* prefs) {
-  prefs->RegisterListPref(prefs::kManagedModeWhitelist,
-                          PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterListPref(prefs::kManagedModeBlacklist,
-                          PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterIntegerPref(prefs::kDefaultManagedModeFilteringBehavior,
-                             ManagedModeURLFilter::BLOCK,
-                             PrefServiceSyncable::UNSYNCABLE_PREF);
+void ManagedUserService::RegisterUserPrefs(PrefRegistrySyncable* registry) {
+  registry->RegisterListPref(prefs::kManagedModeWhitelist,
+                             PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterListPref(prefs::kManagedModeBlacklist,
+                             PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterIntegerPref(prefs::kDefaultManagedModeFilteringBehavior,
+                                ManagedModeURLFilter::BLOCK,
+                                PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 scoped_refptr<const ManagedModeURLFilter>