Implement navigator.languages.

Source/core/frame/NavigatorLanguage.h

 // Copyright 2014 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 NavigatorLanguage_h
 #define NavigatorLanguage_h
 
 #include "wtf/text/AtomicString.h"
 
 namespace WebCore {
 
 class NavigatorLanguage {
 public:
+    NavigatorLanguage();
+
     AtomicString language(bool&);
+    virtual Vector<String> languages() = 0;
+    bool hasLanguagesChanged();
+    void setLanguagesChanged();
+
+private:
+    bool m_languagesChanged;
 };
 
 } // namespace WebCore
 
 #endif // NavigatorLanguage_h