Move extensions storage API implementation to src/extensions

chrome/browser/extensions/api/storage/settings_backend.h

-// 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.
-
-#ifndef CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_BACKEND_H_
-#define CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_BACKEND_H_
-
-#include <string>
-
-#include "base/files/file_path.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "chrome/browser/extensions/api/storage/settings_storage_quota_enforcer.h"
-
-namespace syncer {
-class SyncableService;
-}
-
-class ValueStore;
-
-namespace extensions {
-class SettingsStorageFactory;
-
-// Performs work for the storage API on the FILE thread.
-class SettingsBackend {
- public:
-  SettingsBackend(const scoped_refptr<SettingsStorageFactory>& storage_factory,
-                  const base::FilePath& base_path,
-                  const SettingsStorageQuotaEnforcer::Limits& quota);
-  virtual ~SettingsBackend();
-
-  // Gets a weak reference to the storage area for |extension_id|.
-  // Must be run on the FILE thread.
-  virtual ValueStore* GetStorage(const std::string& extension_id) = 0;
-
-  // Deletes all setting data for an extension. Call on the FILE thread.
-  virtual void DeleteStorage(const std::string& extension_id) = 0;
-
-  // A slight hack so we can get a SyncableService from a SettingsBackend if
-  // it's actually a SyncStorageBackend. If called on a LocalStorageBackend,
-  // this asserts and returns null.
-  virtual syncer::SyncableService* GetAsSyncableService();
-
-  SettingsStorageFactory* storage_factory() const {
-    return storage_factory_.get();
-  }
-  const base::FilePath& base_path() const { return base_path_; }
-  const SettingsStorageQuotaEnforcer::Limits& quota() const { return quota_; }
-
- protected:
-  // Creates a ValueStore decorated with quota-enforcing behavior (the default
-  // for both sync and local stores). If the database is corrupt,
-  // SettingsStorageQuotaEnforcer will try and restore it as part of the
-  // initialization process (by necessity, since we need to read the database to
-  // calculate the storage).
-  scoped_ptr<SettingsStorageQuotaEnforcer> CreateStorageForExtension(
-      const std::string& extension_id) const;
-
- private:
-  // The Factory to use for creating new ValueStores.
-  const scoped_refptr<SettingsStorageFactory> storage_factory_;
-
-  // The base file path to use when creating new ValueStores.
-  const base::FilePath base_path_;
-
-  // Quota limits (see SettingsStorageQuotaEnforcer).
-  const SettingsStorageQuotaEnforcer::Limits quota_;
-
-  DISALLOW_COPY_AND_ASSIGN(SettingsBackend);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_BACKEND_H_