Translate: adopt html lang attribute if valid value is provided

chrome/renderer/translate/translate_helper.h

 // Copyright (c) 2011 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_RENDERER_TRANSLATE_TRANSLATE_HELPER_H_
 #define CHROME_RENDERER_TRANSLATE_TRANSLATE_HELPER_H_
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
@@ skipping 78 matching lines @@
  private:
   FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, LanguageCodeTypoCorrection);
   FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, LanguageCodeSynonyms);
   FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, ResetInvalidLanguageCode);
   FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest,
                            CLDDisagreeWithWrongLanguageCode);
   FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest,
                            CLDAgreeWithLanguageCodeHavingCountryCode);
   FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest,
                            InvalidLanguageMetaTagProviding);
+  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, AdoptHtmlLang);
 
-  // Correct language code if it contains well-known mistakes.
+  // Corrects language code if it contains well-known mistakes.
   static void CorrectLanguageCodeTypo(std::string* code);
 
-  // Convert language code to the one used in server supporting list.
+  // Converts language code to the one used in server supporting list.
   static void ConvertLanguageCodeSynonym(std::string* code);
 
-  // Reset language code if the specified string is apparently invalid.
+  // Resets language code if the specified string is apparently invalid.
   static void ResetInvalidLanguageCode(std::string* code);
 
-  // Determine content page language from Content-Language code and contents.
+  // Applies a series of language code modification in proper order.
+  static void ApplyLanguageCodeCorrection(std::string* code);
+
+  // Determines content page language from Content-Language code and contents.
   static std::string DeterminePageLanguage(const std::string& code,
+                                           const std::string& html_lang,
                                            const string16& contents,
                                            std::string* cld_language,
                                            bool* is_cld_reliable);
 
   // Returns whether the page associated with |document| is a candidate for
   // translation.  Some pages can explictly specify (via a meta-tag) that they
   // should not be translated.
   static bool IsTranslationAllowed(WebKit::WebDocument* document);
 
 #if defined(ENABLE_LANGUAGE_DETECTION)
@@ skipping 39 matching lines @@
   // time from showing infobar to requesting translation.
   base::TimeTicks language_determined_time_;
 
   // Method factory used to make calls to TranslatePageImpl.
   base::WeakPtrFactory<TranslateHelper> weak_method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TranslateHelper);
 };
 
 #endif  // CHROME_RENDERER_TRANSLATE_TRANSLATE_HELPER_H_