Reading List create protobuf store

ios/chrome/browser/reading_list/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 "ios/chrome/browser/reading_list/reading_list_model.h"
 
 ReadingListModel::ReadingListModel() : current_batch_updates_count_(0) {}
+
 ReadingListModel::~ReadingListModel() {}
 
 // Observer methods.
 void ReadingListModel::AddObserver(ReadingListModelObserver* observer) {
   DCHECK(observer);
   observers_.AddObserver(observer);
   if (loaded()) {
     observer->ReadingListModelLoaded(this);
   }
 }
 
 void ReadingListModel::RemoveObserver(ReadingListModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 // Batch update methods.
 bool ReadingListModel::IsPerformingBatchUpdates() const {
   return current_batch_updates_count_ > 0;
 }
 
 std::unique_ptr<ReadingListModel::ScopedReadingListBatchUpdate>
 ReadingListModel::BeginBatchUpdates() {
   std::unique_ptr<ReadingListModel::ScopedReadingListBatchUpdate> token(
       new ReadingListModel::ScopedReadingListBatchUpdate(this));
 
   ++current_batch_updates_count_;
   if (current_batch_updates_count_ == 1) {
-    FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
-                      ReadingListModelBeganBatchUpdates(this));
+    EnteringBatchUpdates();
   }
   return token;
 }
 
+void ReadingListModel::EnteringBatchUpdates() {
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListModelBeganBatchUpdates(this));
+}
+
 void ReadingListModel::EndBatchUpdates() {
   DCHECK(IsPerformingBatchUpdates());
   --current_batch_updates_count_;
   if (current_batch_updates_count_ == 0) {
-    FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
-                      ReadingListModelCompletedBatchUpdates(this));
+    LeavingBatchUpdates();
   }
 }
+
+void ReadingListModel::LeavingBatchUpdates() {
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListModelCompletedBatchUpdates(this));
+}