Remove all ReadingList entries on managed account signout.

components/reading_list/ios/reading_list_model_impl.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_IOS_READING_LIST_MODEL_IMPL_H_
 #define COMPONENTS_READING_LIST_IOS_READING_LIST_MODEL_IMPL_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 61 matching lines @@
   void SetEntryDistilledInfo(const GURL& url,
                              const base::FilePath& distilled_path,
                              const GURL& distilled_url,
                              int64_t distillation_size,
                              int64_t distillation_date) override;
 
   void SyncAddEntry(std::unique_ptr<ReadingListEntry> entry) override;
   ReadingListEntry* SyncMergeEntry(
       std::unique_ptr<ReadingListEntry> entry) override;
   void SyncRemoveEntry(const GURL& url) override;
+  bool DeleteAllEntries() override;
 
   std::unique_ptr<ReadingListModel::ScopedReadingListBatchUpdate>
   CreateBatchToken() override;
 
   // Helper class that is used to scope batch updates.
   class ScopedReadingListBatchUpdate
       : public ReadingListModel::ScopedReadingListBatchUpdate {
    public:
     explicit ScopedReadingListBatchUpdate(ReadingListModelImpl* model);
 
@@ skipping 41 matching lines @@
 
   std::unique_ptr<ReadingListModelStorage> storage_layer_;
   PrefService* pref_service_;
   bool has_unseen_;
   bool loaded_;
   base::WeakPtrFactory<ReadingListModelImpl> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(ReadingListModelImpl);
 };
 
 #endif  // COMPONENTS_READING_LIST_IOS_READING_LIST_MODEL_IMPL_H_