Move language detection to chrome/common/.

chrome/common/translate/language_detection_util.h

+// Copyright 2013 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_COMMON_TRANSLATE_LANGUAGE_DETECTION_UTIL_H_
+#define CHROME_COMMON_TRANSLATE_LANGUAGE_DETECTION_UTIL_H_
+
+#include <string>
+
+#include "base/strings/string16.h"
+
+namespace LanguageDetectionUtil {
+
+// Determines content page language from Content-Language code and contents.
+std::string DeterminePageLanguage(const std::string& code,
+                                  const std::string& html_lang,
+                                  const base::string16& contents,
+                                  std::string* cld_language,
+                                  bool* is_cld_reliable);
+
+// Corrects language code if it contains well-known mistakes.
+// Called only by tests.
+void CorrectLanguageCodeTypo(std::string* code);
+
+// Checks if the language code's format is valid.
+// Called only by tests.
+bool IsValidLanguageCode(const std::string& code);
+
+// Checks if languages are matched, or similar. This function returns true
+// against a language pair containing a language which is difficult for CLD to
+// distinguish.
+// Called only by tests.
+bool IsSameOrSimilarLanguages(const std::string& page_language,
+                              const std::string& cld_language);
+
+// Checks if languages pair is one of well-known pairs of wrong server
+// configuration.
+// Called only by tests.
+bool MaybeServerWrongConfiguration(const std::string& page_language,
+                                   const std::string& cld_language);
+
+}  // namespace LanguageDetectionUtil
+
+#endif  // CHROME_COMMON_TRANSLATE_LANGUAGE_DETECTION_UTIL_H_