Remove all ReadingList entries on managed account signout.

ios/chrome/browser/reading_list/reading_list_remover_helper.h

+// Copyright 2017 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 IOS_CHROME_BROWSER_READING_LIST_READING_LIST_REMOVER_HELPER_H_
+#define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_REMOVER_HELPER_H_
+
+#include "base/callback.h"
+#include "base/scoped_observer.h"
+#include "components/reading_list/ios/reading_list_model_observer.h"
+
+namespace ios {
+class ChromeBrowserState;
+}
+
+class ReadingListModel;
+class ReadingListDownloadService;
+
+namespace reading_list {
+class ReadingListRemoverHelper : public ReadingListModelObserver {
+ public:
+  using Callback = base::OnceCallback<void(bool)>;
+  ReadingListRemoverHelper(ios::ChromeBrowserState* browser_state);
+  ~ReadingListRemoverHelper() override;
+
+  // Removes all Reading list items and call completion with |true| if the
+  // cleaning was successful.
+  void RemoveAllUserReadingListItemsIOS(Callback completion);
+
+  // ReadingListModelObserver implementation.
+  void ReadingListModelLoaded(const ReadingListModel* model) override;
+  void ReadingListModelBeingDeleted(const ReadingListModel* model) override;
+
+ private:
+  Callback completion_;
+  ReadingListModel* reading_list_model_;
+  ReadingListDownloadService* reading_list_download_service_;
+  ScopedObserver<ReadingListModel, ReadingListModelObserver> scoped_observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(ReadingListRemoverHelper);
+};
+}  // namespace reading_list
+
+#endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_REMOVER_HELPER_H_