Revert of Add a Restore() method to ValueStore and make StorageAPI use it

chrome/browser/extensions/api/storage/local_storage_backend.cc

-// Copyright 2014 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/api/storage/local_storage_backend.h"
-
-#include "base/file_util.h"
-#include "chrome/browser/extensions/api/storage/settings_storage_factory.h"
-
-namespace extensions {
-
-LocalStorageBackend::LocalStorageBackend(
-    const scoped_refptr<SettingsStorageFactory>& storage_factory,
-    const base::FilePath& base_path,
-    const SettingsStorageQuotaEnforcer::Limits& quota)
-    : SettingsBackend(storage_factory, base_path, quota) {}
-
-LocalStorageBackend::~LocalStorageBackend() {}
-
-ValueStore* LocalStorageBackend::GetStorage(const std::string& extension_id) {
-  StorageMap::iterator iter = storage_map_.find(extension_id);
-  if (iter != storage_map_.end())
-    return iter->second.get();
-
-  linked_ptr<SettingsStorageQuotaEnforcer> storage(
-      CreateStorageForExtension(extension_id).release());
-  storage_map_[extension_id] = storage;
-  return storage.get();
-}
-
-void LocalStorageBackend::DeleteStorage(const std::string& extension_id) {
-  // Clear settings when the extension is uninstalled.
-  storage_map_.erase(extension_id);
-  storage_factory()->DeleteDatabaseIfExists(base_path(), extension_id);
-}
-
-}  // namespace extensions