Improve reliability of custom spelling dictionary file.

chrome/browser/spellchecker/spellcheck_custom_dictionary.h

Index: chrome/browser/spellchecker/spellcheck_custom_dictionary.h
diff --git a/chrome/browser/spellchecker/spellcheck_custom_dictionary.h b/chrome/browser/spellchecker/spellcheck_custom_dictionary.h
index b1d6045f1db0231c841c7e57c7738cf5b490a0c7..f2035c9f1405e5543aafdfccc3a916491bd6d30e 100644
--- a/chrome/browser/spellchecker/spellcheck_custom_dictionary.h
+++ b/chrome/browser/spellchecker/spellcheck_custom_dictionary.h
@@ -75,12 +75,31 @@ class SpellcheckCustomDictionary : public SpellcheckDictionary {
   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_;