Remove PrefValueStore's dependency on PrefModelAssociator.

chrome/browser/prefs/pref_service_syncable.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/prefs/pref_service_syncable.h"
 
 #include "base/bind.h"
 #include "base/file_path.h"
 #include "base/prefs/default_pref_store.h"
 #include "base/prefs/overlay_user_pref_store.h"
@@ skipping 244 matching lines @@
     base::Callback<void(PersistentPrefStore::PrefReadError)>
         read_error_callback,
     bool async) {
   PrefService::Initialize(pref_notifier,
                           pref_value_store,
                           user_prefs,
                           default_store,
                           read_error_callback,
                           async);
 
-  pref_value_store->set_sync_associator(&pref_sync_associator_);
+  pref_value_store->set_callback(
+      base::Bind(&PrefModelAssociator::ProcessPrefChange,
+                 base::Unretained(&pref_sync_associator_)));
 }
 
 void PrefServiceSyncable::OnIsSyncingChanged() {
   FOR_EACH_OBSERVER(PrefServiceObserver, observer_list_, OnIsSyncingChanged());
 }
 
 void PrefServiceSyncable::RegisterSyncablePreference(
     const char* path, Value* default_value, PrefSyncStatus sync_status) {
   PrefService::RegisterPreference(path, default_value);
   // Register with sync if necessary.
   if (sync_status == SYNCABLE_PREF)
     pref_sync_associator_.RegisterPref(path);
 }