[Merge M-58] Implements ChineseScriptClassifier functionality without icu::Transliterator

components/translate/core/language_detection/chinese_script_classifier.h

 // Copyright 2017 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 COMPONENTS_TRANSLATE_CORE_LANGUAGE_DETECTION_CHINESE_SCRIPT_CLASSIFIER_H_
 #define COMPONENTS_TRANSLATE_CORE_LANGUAGE_DETECTION_CHINESE_SCRIPT_CLASSIFIER_H_
 
 #include <memory>
 #include <string>
-#include "third_party/icu/source/i18n/unicode/translit.h"
+#include "third_party/icu/source/common/unicode/uniset.h"
 
 namespace translate {
 
 class ChineseScriptClassifier {
  public:
-  // Initializes both the Hant-to-Hans ICU transliterator and the
-  // Hans-to-Hant ICU transliterator.
+  // Initializes both the zh-Hans and zh-Hant UnicodeSets used for
+  // lookup when Classify is called.
   ChineseScriptClassifier();
   ~ChineseScriptClassifier();
 
   // Given Chinese text as input, returns either zh-Hant or zh-Hans.
   // When the input is ambiguous, i.e. not completely zh-Hans and not
   // completely zh-Hant, this function returns the closest language code
   // matching the input.
   //
   // Behavior is undefined for non-Chinese input.
   std::string Classify(const std::string& input) const;
 
   // Returns true if the underlying transliterators were properly initialized
   // by the constructor.
   bool IsInitialized() const;
 
  private:
-  // ICU Transliterator that does Hans to Hant conversion.
-  std::unique_ptr<icu::Transliterator> hans2hant_;
+  // Set of chars generally unique to zh-Hans.
+  std::unique_ptr<icu::UnicodeSet> hans_set_;
 
-  // ICU Transliterator that does Hant to Hans conversion.
-  std::unique_ptr<icu::Transliterator> hant2hans_;
+  // Set of chars generally unique to zh-Hant.
+  std::unique_ptr<icu::UnicodeSet> hant_set_;
 };
 
 }  // namespace translate
 
 #endif  // COMPONENTS_TRANSLATE_CORE_LANGUAGE_DETECTION_CHINESE_SCRIPT_CLASSIFIER_H_