Break two classes defined in json_value_serializer.cc, .h into separate files.

chrome/browser/prefs/pref_model_associator.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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_model_associator.h"
 
 #include "base/auto_reset.h"
 #include "base/json/json_reader.h"
-#include "base/json/json_value_serializer.h"
+#include "base/json/json_string_value_serializer.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/sync/api/sync_change.h"
 #include "chrome/browser/sync/protocol/preference_specifics.pb.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 
 using syncable::PREFERENCES;
@@ skipping 407 matching lines @@
   SyncError error =
       sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
   if (error.IsSet())
     StopSyncing(PREFERENCES);
 }
 
 void PrefModelAssociator::SetPrefService(PrefService* pref_service) {
   DCHECK(pref_service_ == NULL);
   pref_service_ = pref_service;
 }