Unrevert r141537: Add extensions::StateStore and use that instead of

chrome/browser/extensions/settings/settings_backend.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/extensions/settings/settings_backend.h"
 
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
@@ skipping 45 matching lines @@
   if (maybe_storage != storage_objs_.end()) {
     return maybe_storage->second.get();
   }
 
   ValueStore* storage = storage_factory_->Create(base_path_, extension_id);
   if (storage) {
     // It's fine to create the quota enforcer underneath the sync layer, since
     // sync will only go ahead if each underlying storage operation succeeds.
     storage = new SettingsStorageQuotaEnforcer(quota_, storage);
   } else {
-    storage = new FailingSettingsStorage();
+    storage = new FailingValueStore();
   }
 
   linked_ptr<SyncableSettingsStorage> syncable_storage(
       new SyncableSettingsStorage(
           observers_,
           extension_id,
           storage));
   storage_objs_[extension_id] = syncable_storage;
 
   if (sync_processor_.get()) {
@@ skipping 209 matching lines @@
 scoped_ptr<SettingsSyncProcessor> SettingsBackend::CreateSettingsSyncProcessor(
     const std::string& extension_id) const {
   CHECK(sync_processor_.get());
   return scoped_ptr<SettingsSyncProcessor>(
       new SettingsSyncProcessor(extension_id,
                                 sync_type_,
                                 sync_processor_.get()));
 }
 
 }  // namespace extensions