Improve reliability of custom spelling dictionary file.

chrome/browser/spellchecker/spellcheck_custom_dictionary.h

 // Copyright (c) 2012 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 CHROME_BROWSER_SPELLCHECKER_SPELLCHECK_CUSTOM_DICTIONARY_H_
 #define CHROME_BROWSER_SPELLCHECKER_SPELLCHECK_CUSTOM_DICTIONARY_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 57 matching lines @@
   // The caller owns this new list.
   chrome::spellcheck_common::WordList* LoadDictionary();
 
   // The reply point for PostTaskAndReplyWithResult. Called when LoadDictionary
   // is finished reading words from custom dictionary file. Moves the strings
   // from the |custom_words| argument into the private member variable |words_|
   // and deletes the memory at |custom_words|.
   void SetCustomWordListAndDelete(
       chrome::spellcheck_common::WordList* custom_words);
 
+  // Loads the dictionary file into |contents|. If the dictionary checksum is
+  // not valid, but backup checksum is valid, then restores the backup and loads
+  // that into |contents| instead.
+  void LoadDictionaryContentsReliably(std::string* contents);
+
+  // Backs up the original dictionary and checksum files, saves |contents| into
+  // the dictionary file, and saves the checksum of |contents| into the checksum
+  // file.
+  void SaveDictionryContentsReliably(const std::string& contents);
+
   // In-memory cache of the custom words file.
   chrome::spellcheck_common::WordList words_;
 
   // A path for custom dictionary per profile.
   FilePath custom_dictionary_path_;
 
+  // A path for checksum of custom dictionary per profile.
+  FilePath custom_dictionary_checksum_path_;
+

[groby-ooo-7-16, 2012/12/03 17:12:44]

Can't we just derive all those filepaths computationalluy from
custom_dictionary_path_? Do we really need to store them?

Also, can we store the checksum _in_ the dictionary file instead?

[please use gerrit instead, 2012/12/03 23:16:51]

Done.

+  // A path for custom dictionary backup per profile.
+  FilePath custom_dictionary_backup_path_;
+
+  // A path for checksum of custom dictionary backup per profile.
+  FilePath custom_dictionary_checksum_backup_path_;
+
   base::WeakPtrFactory<SpellcheckCustomDictionary> weak_ptr_factory_;
 
   std::vector<Observer*> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(SpellcheckCustomDictionary);
 };
 
 #endif  // CHROME_BROWSER_SPELLCHECKER_SPELLCHECK_CUSTOM_DICTIONARY_H_