[Translate] Apply language synonyms to the target language

chrome/browser/translate/translate_prefs.h

 // Copyright (c) 2010 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_TRANSLATE_TRANSLATE_PREFS_H_
 #define CHROME_BROWSER_TRANSLATE_TRANSLATE_PREFS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 77 matching lines @@
   // Updates the language list of chrome://settings/languages.
   void UpdateLanguageList(const std::vector<std::string>& languages);
 
   static bool CanTranslateLanguage(
       Profile* profile, const std::string& language);
   static bool ShouldAutoTranslate(PrefService* user_prefs,
       const std::string& original_language, std::string* target_language);
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
   static void MigrateUserPrefs(PrefService* user_prefs);
 
+  // Converts the language code for Translate. This removes the sub code (like
+  // -US) except for Chinese, and converts the synonyms.
+  // The same logic exists at language_options.js, and please keep consistency
+  // with the JavaScript file.
+  static std::string ConvertLangCodeForTranslation(const std::string &lang);
+
  private:
   friend class TranslatePrefsTest;
   FRIEND_TEST_ALL_PREFIXES(TranslatePrefsTest, CreateBlockedLanguages);
   FRIEND_TEST_ALL_PREFIXES(TranslatePrefsTest,
                            CreateBlockedLanguagesNonEnglishUI);
 
   // Merges two language sets to migrate to the language setting UI.
   static void CreateBlockedLanguages(
       std::vector<std::string>* blocked_languages,
       const std::vector<std::string>& blacklisted_languages,
@@ skipping 16 matching lines @@
   // Retrieves the dictionary mapping the number of times translation has been
   // accepted for a language, creating it if necessary.
   base::DictionaryValue* GetTranslationAcceptedCountDictionary() const;
 
   PrefService* prefs_;  // Weak.
 
   DISALLOW_COPY_AND_ASSIGN(TranslatePrefs);
 };
 
 #endif  // CHROME_BROWSER_TRANSLATE_TRANSLATE_PREFS_H_