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

chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.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/api/storage/sync_or_local_value_store_cache.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/sequenced_task_runner.h"
-#include "chrome/browser/extensions/api/storage/local_storage_backend.h"
+#include "chrome/browser/extensions/api/storage/settings_backend.h"
 #include "chrome/browser/extensions/api/storage/settings_frontend.h"
 #include "chrome/browser/extensions/api/storage/settings_storage_quota_enforcer.h"
-#include "chrome/browser/extensions/api/storage/sync_storage_backend.h"
 #include "chrome/browser/extensions/api/storage/weak_unlimited_settings_storage.h"
 #include "chrome/browser/sync/glue/sync_start_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/permissions/api_permission.h"
 
 using content::BrowserThread;
 
 namespace extensions {
 
 SyncOrLocalValueStoreCache::SyncOrLocalValueStoreCache(
     settings_namespace::Namespace settings_namespace,
     const scoped_refptr<SettingsStorageFactory>& factory,
     const SettingsStorageQuotaEnforcer::Limits& quota,
     const scoped_refptr<SettingsObserverList>& observers,
     const base::FilePath& profile_path)
-    : settings_namespace_(settings_namespace), initialized_(false) {
+    : settings_namespace_(settings_namespace) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(settings_namespace_ == settings_namespace::LOCAL ||
          settings_namespace_ == settings_namespace::SYNC);
 
   // This post is safe since the destructor can only be invoked from the
   // same message loop, and any potential post of a deletion task must come
   // after the constructor returns.
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&SyncOrLocalValueStoreCache::InitOnFileThread,
                  base::Unretained(this),
                  factory, quota, observers, profile_path));
 }
 
 SyncOrLocalValueStoreCache::~SyncOrLocalValueStoreCache() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 }
 
-syncer::SyncableService* SyncOrLocalValueStoreCache::GetSyncableService(
-    syncer::ModelType type) const {
+SettingsBackend* SyncOrLocalValueStoreCache::GetAppBackend() const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  DCHECK(initialized_);
-  switch (type) {
-    case syncer::APP_SETTINGS:
-      return app_backend_->GetAsSyncableService();
-    case syncer::EXTENSION_SETTINGS:
-      return extension_backend_->GetAsSyncableService();
-    default:
-      NOTREACHED();
-      return NULL;
-  }
+  DCHECK(app_backend_.get());
+  return app_backend_.get();
+}
+
+SettingsBackend* SyncOrLocalValueStoreCache::GetExtensionBackend() const {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK(extension_backend_.get());
+  return extension_backend_.get();
 }
 
 void SyncOrLocalValueStoreCache::RunWithValueStoreForExtension(
     const StorageCallback& callback,
     scoped_refptr<const Extension> extension) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  DCHECK(initialized_);
-
+  DCHECK(app_backend_.get());
+  DCHECK(extension_backend_.get());
   SettingsBackend* backend =
       extension->is_app() ? app_backend_.get() : extension_backend_.get();
   ValueStore* storage = backend->GetStorage(extension->id());
 
   // A neat way to implement unlimited storage; if the extension has the
   // unlimited storage permission, force through all calls to Set() (in the
   // same way that writes from sync ignore quota).
   // But only if it's local storage (bad stuff would happen if sync'ed
   // storage is allowed to be unlimited).
   bool is_unlimited =
       settings_namespace_ == settings_namespace::LOCAL &&
       extension->HasAPIPermission(APIPermission::kUnlimitedStorage);
 
   if (is_unlimited) {
     WeakUnlimitedSettingsStorage unlimited_storage(storage);
     callback.Run(&unlimited_storage);
   } else {
     callback.Run(storage);
   }
 }
 
 void SyncOrLocalValueStoreCache::DeleteStorageSoon(
     const std::string& extension_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  DCHECK(initialized_);
   app_backend_->DeleteStorage(extension_id);
   extension_backend_->DeleteStorage(extension_id);
 }
 
 void SyncOrLocalValueStoreCache::InitOnFileThread(
     const scoped_refptr<SettingsStorageFactory>& factory,
     const SettingsStorageQuotaEnforcer::Limits& quota,
     const scoped_refptr<SettingsObserverList>& observers,
     const base::FilePath& profile_path) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  DCHECK(!initialized_);
-  switch (settings_namespace_) {
-    case settings_namespace::LOCAL:
-      app_backend_.reset(new LocalStorageBackend(
-          factory,
-          profile_path.AppendASCII(kLocalAppSettingsDirectoryName),
-          quota));
-      extension_backend_.reset(new LocalStorageBackend(
-          factory,
-          profile_path.AppendASCII(kLocalExtensionSettingsDirectoryName),
-          quota));
-      break;
-    case settings_namespace::SYNC:
-      app_backend_.reset(new SyncStorageBackend(
-          factory,
-          profile_path.AppendASCII(kSyncAppSettingsDirectoryName),
-          quota,
-          observers,
-          syncer::APP_SETTINGS,
-          sync_start_util::GetFlareForSyncableService(profile_path)));
-      extension_backend_.reset(new SyncStorageBackend(
-          factory,
-          profile_path.AppendASCII(kSyncExtensionSettingsDirectoryName),
-          quota,
-          observers,
-          syncer::EXTENSION_SETTINGS,
-          sync_start_util::GetFlareForSyncableService(profile_path)));
-      break;
-    default:
-      NOTREACHED();
-  }
-
-  initialized_ = true;
+  DCHECK(!app_backend_.get());
+  DCHECK(!extension_backend_.get());
+  const bool local = settings_namespace_ == settings_namespace::LOCAL;
+  const base::FilePath app_path = profile_path.AppendASCII(
+      local ? extensions::kLocalAppSettingsDirectoryName
+            : extensions::kSyncAppSettingsDirectoryName);
+  const base::FilePath extension_path = profile_path.AppendASCII(
+      local ? extensions::kLocalExtensionSettingsDirectoryName
+            : extensions::kSyncExtensionSettingsDirectoryName);
+  app_backend_.reset(new SettingsBackend(
+      factory, app_path, syncer::APP_SETTINGS,
+      sync_start_util::GetFlareForSyncableService(profile_path),
+      quota, observers));
+  extension_backend_.reset(new SettingsBackend(
+      factory, extension_path, syncer::EXTENSION_SETTINGS,
+      sync_start_util::GetFlareForSyncableService(profile_path),
+      quota, observers));
 }
 
 }  // namespace extensions