The UI language rather than the locale is now used to pick Chrome's language ...

chrome_frame/simple_resource_loader.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.
 //
 // This class implements a simplified and much stripped down version of
 // Chrome's app/resource_bundle machinery. It notably avoids unwanted
 // dependencies on things like Skia.
 //
 
 #ifndef CHROME_FRAME_SIMPLE_RESOURCE_LOADER_H_
@@ skipping 22 matching lines @@
   static std::wstring Get(int message_id);
 
   // Retrieves the HINSTANCE of the loaded module handle. May be NULL if a
   // resource DLL could not be loaded.
   HMODULE GetResourceModuleHandle();
 
   // Retrieves the preferred languages for the current thread, adding them to
   // |language_tags|.
   static void GetPreferredLanguages(std::vector<std::wstring>* language_tags);
 
-  // Retrieves the thread/process/user/system preferred languages on Vista+,
-  // adding them and their fallbacks to |language_tags|.  Returns |false| if the
-  // platform does not support such (i.e., XP).
-  static bool GetThreadPreferredUILanguages(
-      std::vector<std::wstring>* language_tags);
-
-  // Retrieves the system language and the region using ICU (used on XP).
-  static void GetICUSystemLanguage(std::wstring* language,
-                                   std::wstring* region);
-
   // Populates |locales_path| with the path to the "Locales" directory.
   static void DetermineLocalesDirectory(FilePath* locales_path);
 
   // Returns false if |language_tag| is malformed.
   static bool IsValidLanguageTag(const std::wstring& language_tag);
 
  private:
   SimpleResourceLoader();
   ~SimpleResourceLoader();
 
@@ skipping 13 matching lines @@
 
   friend struct DefaultSingletonTraits<SimpleResourceLoader>;
 
   FRIEND_TEST_ALL_PREFIXES(SimpleResourceLoaderTest, LoadLocaleDll);
 
   std::wstring language_;
   HINSTANCE locale_dll_handle_;
 };
 
 #endif  // CHROME_FRAME_SIMPLE_RESOURCE_LOADER_H_