Move ReadingList model to components/reading_list/core

components/reading_list/ios/reading_list_model.cc

-// 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.
-
-#include "components/reading_list/ios/reading_list_model.h"
-
-#include "base/logging.h"
-#include "base/memory/ptr_util.h"
-
-ReadingListModel::ReadingListModel() : current_batch_updates_count_(0) {}
-
-ReadingListModel::~ReadingListModel() {
-  for (auto& observer : observers_) {
-    observer.ReadingListModelBeingDeleted(this);
-  }
-}
-
-// Observer methods.
-void ReadingListModel::AddObserver(ReadingListModelObserver* observer) {
-  DCHECK(CalledOnValidThread());
-  DCHECK(observer);
-  observers_.AddObserver(observer);
-  if (loaded()) {
-    observer->ReadingListModelLoaded(this);
-  }
-}
-
-void ReadingListModel::RemoveObserver(ReadingListModelObserver* observer) {
-  DCHECK(CalledOnValidThread());
-  observers_.RemoveObserver(observer);
-}
-
-// Batch update methods.
-bool ReadingListModel::IsPerformingBatchUpdates() const {
-  DCHECK(CalledOnValidThread());
-  return current_batch_updates_count_ > 0;
-}
-
-std::unique_ptr<ReadingListModel::ScopedReadingListBatchUpdate>
-ReadingListModel::CreateBatchToken() {
-  return base::MakeUnique<ReadingListModel::ScopedReadingListBatchUpdate>(this);
-}
-
-std::unique_ptr<ReadingListModel::ScopedReadingListBatchUpdate>
-ReadingListModel::BeginBatchUpdates() {
-  DCHECK(CalledOnValidThread());
-  auto token = CreateBatchToken();
-
-  ++current_batch_updates_count_;
-  if (current_batch_updates_count_ == 1) {
-    EnteringBatchUpdates();
-  }
-  return token;
-}
-
-void ReadingListModel::EnteringBatchUpdates() {
-  DCHECK(CalledOnValidThread());
-  for (auto& observer : observers_)
-    observer.ReadingListModelBeganBatchUpdates(this);
-}
-
-void ReadingListModel::EndBatchUpdates() {
-  DCHECK(CalledOnValidThread());
-  DCHECK(IsPerformingBatchUpdates());
-  DCHECK(current_batch_updates_count_ > 0);
-  --current_batch_updates_count_;
-  if (current_batch_updates_count_ == 0) {
-    LeavingBatchUpdates();
-  }
-}
-
-void ReadingListModel::LeavingBatchUpdates() {
-  DCHECK(CalledOnValidThread());
-  for (auto& observer : observers_)
-    observer.ReadingListModelCompletedBatchUpdates(this);
-}
-
-ReadingListModel::ScopedReadingListBatchUpdate::
-    ~ScopedReadingListBatchUpdate() {
-  model_->EndBatchUpdates();
-}