Remove PrefServiceSimple, replacing it with PrefService and PrefRegistrySimple.

chrome/browser/prefs/pref_service_syncable.cc

Index: chrome/browser/prefs/pref_service_syncable.cc
diff --git a/chrome/browser/prefs/pref_service_syncable.cc b/chrome/browser/prefs/pref_service_syncable.cc
index 46a35176540a910239a6278a956b6a9e0f60dc47..013bcd28fb245d73866c6678f43d2d07f6bf8049 100644
--- a/chrome/browser/prefs/pref_service_syncable.cc
+++ b/chrome/browser/prefs/pref_service_syncable.cc
@@ -263,6 +263,10 @@ void PrefServiceSyncable::UpdateCommandLinePrefStore(
   PrefService::UpdateCommandLinePrefStore(cmd_line_store);
 }
 
+bool PrefServiceSyncable::AllowPrefRegistrarSimple() const {
+  return false;
+}
+
 void PrefServiceSyncable::OnIsSyncingChanged() {
   FOR_EACH_OBSERVER(PrefServiceObserver, observer_list_, OnIsSyncingChanged());
 }