Get the document language directly from WebKit

chrome/renderer/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_HELPER_H_
 #define CHROME_RENDERER_TRANSLATE_HELPER_H_
 
 #include <string>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 52 matching lines @@
   // Used in unit-tests. Makes the various tasks be posted immediately so that
   // the tests don't have to wait before checking states.
   virtual bool DontDelayTasks();
 
  private:
   // 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 IsPageTranslatable(WebKit::WebDocument* document);
 
-  // Returns the language specified in the language meta tag of |document|, or
-  // an empty string if no such tag was found.
-  // The tag may specify several languages, the first one is returned.
-  // Example of such meta-tag:
-  // <meta http-equiv="content-language" content="en, fr">
-  static std::string GetPageLanguageFromMetaTag(WebKit::WebDocument* document);
-
   // Returns the ISO 639_1 language code of the specified |text|, or 'unknown'
   // if it failed.
   static std::string DetermineTextLanguage(const string16& text);
 
   // RenderViewObserver implementation.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   // Cancels any translation that is currently being performed.  This does not
   // revert existing translations.
   void CancelPendingTranslation();
@@ skipping 39 matching lines @@
   std::string source_lang_;
   std::string target_lang_;
 
   // Method factory used to make calls to TranslatePageImpl.
   base::WeakPtrFactory<TranslateHelper> weak_method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TranslateHelper);
 };
 
 #endif  // CHROME_RENDERER_TRANSLATE_HELPER_H_