Reading list downloader retries on recoverable error

ios/chrome/browser/reading_list/reading_list_download_service.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 IOS_CHROME_BROWSER_READING_LIST_READING_LIST_DOWNLOAD_SERVICE_H_
 #define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_DOWNLOAD_SERVICE_H_
 
 #include "base/macros.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "ios/chrome/browser/reading_list/reading_list_model_observer.h"
 #include "ios/chrome/browser/reading_list/url_downloader.h"
+#include "net/base/network_change_notifier.h"
 
 class GURL;
 class PrefService;
 class ReadingListModel;
 namespace base {
 class FilePath;
 }
 
 namespace dom_distiller {
 class DomDistillerService;
 }
 
 // Observes the reading list and downloads offline versions of its articles.
 // Any calls made to DownloadAllEntries/DownloadEntry before the model is
 // loaded will be ignored. When the model is loaded, DownloadAllEntries will be
 // called automatically.
-class ReadingListDownloadService : public KeyedService,
-                                   public ReadingListModelObserver {
+class ReadingListDownloadService
+    : public KeyedService,
+      public ReadingListModelObserver,
+      public net::NetworkChangeNotifier::ConnectionTypeObserver {
  public:
   ReadingListDownloadService(
       ReadingListModel* reading_list_model,
       dom_distiller::DomDistillerService* distiller_service,
       PrefService* prefs,
       base::FilePath chrome_profile_path);
   ~ReadingListDownloadService() override;
 
   // Initializes the reading list download service.
   void Initialize();
 
   // KeyedService implementation.
   void Shutdown() override;
 
   // ReadingListModelObserver implementation
   void ReadingListModelLoaded(const ReadingListModel* model) override;
   void ReadingListWillRemoveReadEntry(const ReadingListModel* model,
                                       size_t index) override;
   void ReadingListWillRemoveUnreadEntry(const ReadingListModel* model,
                                         size_t index) override;
   void ReadingListWillAddUnreadEntry(const ReadingListModel* model,
                                      const ReadingListEntry& entry) override;
   void ReadingListWillAddReadEntry(const ReadingListModel* model,
                                    const ReadingListEntry& entry) override;
 
  private:
   // Tries to save offline versions of all entries in the reading list that are
   // not yet saved. Must only be called after reading list model is loaded.
   void DownloadAllEntries();
+  // Schedule a download of an offline version of the reading list entry,
+  // according to the delay of the entry. Must only be called after reading list
+  // model is loaded.
+  void ScheduleDownloadEntry(const ReadingListEntry& entry);
+  // Tries to save an offline version of the reading list entry corresponding to
+  // the |url| if it is not yet saved. Must only be called after reading list
+  // model is loaded.
+  void DownloadEntryFromURL(const GURL& url);
   // Tries to save an offline version of the reading list entry if it is not yet
   // saved. Must only be called after reading list model is loaded.
   void DownloadEntry(const ReadingListEntry& entry);
   // Removes the offline version of the reading list entry if it exists. Must
   // only be called after reading list model is loaded.
   void RemoveDownloadedEntry(const ReadingListEntry& entry);
   // Callback for entry download.
   void OnDownloadEnd(const GURL& url,
                      URLDownloader::SuccessState success,
                      const GURL& distilled_url,
                      const std::string& title);
 
   // Callback for entry deletion.
   void OnDeleteEnd(const GURL& url, bool success);
 
+  // net::NetworkChangeNotifier::ConnectionTypeObserver:
+  void OnConnectionTypeChanged(
+      net::NetworkChangeNotifier::ConnectionType type) override;
+
   ReadingListModel* reading_list_model_;
   std::unique_ptr<URLDownloader> url_downloader_;
+  std::vector<GURL> url_to_download_cellular_;
+  std::vector<GURL> url_to_download_wifi_;
+  bool had_connection_;
 
   DISALLOW_COPY_AND_ASSIGN(ReadingListDownloadService);
 };
 
 #endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_DOWNLOAD_SERVICE_H_