Enable RL sync by default on iOS

components/reading_list/reading_list_model_storage.h

-// Copyright 2016 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 COMPONENTS_READING_LIST_READING_LIST_MODEL_STORAGE_H_
-#define COMPONENTS_READING_LIST_READING_LIST_MODEL_STORAGE_H_
-
-#include <vector>
-
-#include "components/reading_list/reading_list_entry.h"
-
-class ReadingListModel;
-class ReadingListStoreDelegate;
-
-namespace syncer {
-class ModelTypeSyncBridge;
-}
-
-// Interface for a persistence layer for reading list.
-// All interface methods have to be called on main thread.
-class ReadingListModelStorage {
- public:
-  class ScopedBatchUpdate;
-
-  // Sets the model the Storage is backing.
-  // This will trigger store initalization and load persistent entries.
-  virtual void SetReadingListModel(ReadingListModel* model,
-                                   ReadingListStoreDelegate* delegate) = 0;
-
-  // Returns the class responsible for handling sync messages.
-  virtual syncer::ModelTypeSyncBridge* GetModelTypeSyncBridge() = 0;
-
-  // Starts a transaction. All Save/Remove entry will be delayed until the
-  // transaction is commited.
-  // Multiple transaction can be started at the same time. Commit will happen
-  // when the last transaction is commited.
-  // Returns a scoped batch update object that should be retained while the
-  // batch update is performed. Deallocating this object will inform model that
-  // the batch update has completed.
-  virtual std::unique_ptr<ScopedBatchUpdate> EnsureBatchCreated() = 0;
-
-  // Saves or updates an entry. If the entry is not yet in the database, it is
-  // created.
-  virtual void SaveEntry(const ReadingListEntry& entry, bool read) = 0;
-
-  // Removed an entry from the storage.
-  virtual void RemoveEntry(const ReadingListEntry& entry) = 0;
-
-  class ScopedBatchUpdate {
-   public:
-    virtual ~ScopedBatchUpdate() {}
-  };
-};
-
-#endif  // COMPONENTS_READING_LIST_READING_LIST_MODEL_STORAGE_H_