[ReadingList iOS] Cleanup Offline directory on startup

ios/chrome/browser/reading_list/reading_list_download_service.h

Index: ios/chrome/browser/reading_list/reading_list_download_service.h
diff --git a/ios/chrome/browser/reading_list/reading_list_download_service.h b/ios/chrome/browser/reading_list/reading_list_download_service.h
index 19b68f0a3deb77587f2f6d0ddfb5730b99db721c..f3c882722103b5c05c30fc2ffee59a553613d88a 100644
--- a/ios/chrome/browser/reading_list/reading_list_download_service.h
+++ b/ios/chrome/browser/reading_list/reading_list_download_service.h
@@ -65,12 +65,21 @@ class ReadingListDownloadService
                                const GURL& url) 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();
+  // Checks the model and determine what entries are processed and what entries

[jif, 2017/01/25 09:15:51]

s/what entries/which entries/

[jif, 2017/01/25 09:15:51]

s/determine/determines/

[Olivier, 2017/01/25 12:25:30]

Done.

[Olivier, 2017/01/25 12:25:30]

Done.

+  // needs to be processed.

[jif, 2017/01/25 09:15:51]

need

[Olivier, 2017/01/25 12:25:31]

Done.

+  // Initiates a cleanup of |OfflineRoot| directory removing sub_directories

[gambard, 2017/01/25 09:02:07]

s/OfflineRoot/OfflineRoot()/

[Olivier, 2017/01/25 12:25:31]

Done.

+  // not corresponding to a processed ReadingListEntry.
+  // Schedule unprocessed entries for distillation.
+  void SyncWithModel();
+  // Scans |OfflineRoot| directory and deletes all subdirectories not listed in

[gambard, 2017/01/25 09:02:07]

s/OfflineRoot/OfflineRoot()/

[Olivier, 2017/01/25 12:25:30]

Done.

+  // processed_directories.

[gambard, 2017/01/25 09:02:07]

s/processed_directories/|processed_directories|/

[Olivier, 2017/01/25 12:25:31]

Done.

+  // Must be called on File thread.
+  void CleanUpFiles(const std::set<std::string>& processed_directories);

[gambard, 2017/01/25 09:02:07]

Based on the name of the function I would expect it to clear the data listed in
|processed_directories|.
Maybe CleanUpExcept()? Or change processed_directories to something like
directories_to_keep, exception_directories?

[Olivier, 2017/01/25 12:25:30]

Done.

+  // Schedules all emtries in |unprocessed_entries| for distillation.

[gambard, 2017/01/25 09:02:07]

s/emtries/entries/
This sentence looks weird to me but I have trouble finding a better one. Maybe
it is because we are not scheduling an entry for distillation but scheduling a
download?

[Olivier, 2017/01/25 12:25:31]

Done.

+  void DownloadUnprocessedEntries(const std::set<GURL>& unprocessed_entries);
   // Processes a new entry and schedule a download if needed.

[gambard, 2017/01/25 09:02:07]

s/schedule/schedules

[Olivier, 2017/01/25 12:25:31]

Done.

   void ProcessNewEntry(const GURL& url);
-  // Schedule a download of an offline version of the reading list entry,
+  // Schedules 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 GURL& url);