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

base/win/i18n.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 BASE_WIN_I18N_H_
+#define BASE_WIN_I18N_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace base {
+namespace win {
+namespace i18n {
+
+// Adds to |languages| the list of user preferred UI languages from MUI, if
+// available, falling-back on the user default UI language otherwise.  Returns
+// true if at least one language is added.
+bool GetUserPreferredUILanguageList(std::vector<std::wstring>* languages);
+
+// Adds to |languages| the list of thread, process, user, and system preferred
+// UI languages from MUI, if available, falling-back on the user default UI
+// language otherwise.  Returns true if at least one language is added.
+bool GetThreadPreferredUILanguageList(std::vector<std::wstring>* languages);
+
+}  // namespace i18n
+}  // namespace win
+}  // namespace base
+
+#endif  // BASE_WIN_I18N_H_