Use PrefChangeRegistrar everywhere

chrome/browser/sync/glue/preference_change_processor.cc

Index: chrome/browser/sync/glue/preference_change_processor.cc
diff --git a/chrome/browser/sync/glue/preference_change_processor.cc b/chrome/browser/sync/glue/preference_change_processor.cc
index ec0eeb35b5284930e3654da4dec16e3fe02038ec..874f786d084ac44d76ab1f5ca420e9df2694d7be 100644
--- a/chrome/browser/sync/glue/preference_change_processor.cc
+++ b/chrome/browser/sync/glue/preference_change_processor.cc
@@ -195,6 +195,7 @@ Value* PreferenceChangeProcessor::ReadPreference(
 void PreferenceChangeProcessor::StartImpl(Profile* profile) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
   pref_service_ = profile->GetPrefs();
+  registrar_.Init(pref_service_);
   StartObserving();
 }
 
@@ -210,7 +211,7 @@ void PreferenceChangeProcessor::StartObserving() {
   for (std::set<std::string>::const_iterator it =
       model_associator_->synced_preferences().begin();
       it != model_associator_->synced_preferences().end(); ++it) {
-    pref_service_->AddPrefObserver((*it).c_str(), this);
+    registrar_.Add((*it).c_str(), this);
   }
 }
 
@@ -219,7 +220,7 @@ void PreferenceChangeProcessor::StopObserving() {
   for (std::set<std::string>::const_iterator it =
       model_associator_->synced_preferences().begin();
       it != model_associator_->synced_preferences().end(); ++it) {
-    pref_service_->RemovePrefObserver((*it).c_str(), this);
+    registrar_.Remove((*it).c_str(), this);
   }
 }