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

chrome/installer/util/language_selector.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 file declares a helper class for selecting a supported language from a
+// set of candidates.
+
+#ifndef CHROME_INSTALLER_UTIL_LANGUAGE_SELECTOR_H_
+#define CHROME_INSTALLER_UTIL_LANGUAGE_SELECTOR_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace installer_util {
+
+// A helper class for selecting a supported language from a set of candidates.
+// By default, the candidates are retrieved from the operating system.
+class LanguageSelector {
+ public:
+  // Default constructor will select from the set of languages supported by the
+  // operating system.
+  LanguageSelector();
+
+  // Constructor for testing purposes.
+  explicit LanguageSelector(const std::vector<std::wstring>& candidates);
+
+  ~LanguageSelector();
+
+  // The offset of the matched language (i.e., IDS_L10N_OFFSET_*).
+  int offset() const { return offset_; }
+
+  // The full name of the candidate language for which a match was found.
+  const std::wstring& matched_candidate() const { return matched_candidate_; }
+
+  // The name of the selected translation.
+  std::wstring selected_translation() const { return GetLanguageName(offset_); }
+
+  // Returns the name of a translation given its offset.
+  static std::wstring GetLanguageName(int offset);
+
+ private:
+  typedef bool (*SelectPred_Fn)(const std::wstring&, int*);
+
+  static bool SelectIf(const std::vector<std::wstring>& candidates,
+                       SelectPred_Fn select_predicate,
+                       std::wstring* matched_name, int* matched_offset);
+  void DoSelect(const std::vector<std::wstring>& candidates);
+
+  std::wstring matched_candidate_;
+  int offset_;
+
+  DISALLOW_COPY_AND_ASSIGN(LanguageSelector);
+};
+
+}  // namespace installer_util.
+
+#endif  // CHROME_INSTALLER_UTIL_LANGUAGE_SELECTOR_H_