Reland of "Use address_data.h from upstream libaddressinput".

third_party/libaddressinput/chromium/cpp/src/language.h

Index: third_party/libaddressinput/chromium/cpp/src/language.h
diff --git a/third_party/libaddressinput/chromium/cpp/src/language.h b/third_party/libaddressinput/chromium/cpp/src/language.h
new file mode 100644
index 0000000000000000000000000000000000000000..561c79fa690fc50a9c462cf5a819cb5dbc1a040e
--- /dev/null
+++ b/third_party/libaddressinput/chromium/cpp/src/language.h
@@ -0,0 +1,49 @@
+// Copyright (C) 2014 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef I18N_ADDRESSINPUT_LANGUAGE_H_
+#define I18N_ADDRESSINPUT_LANGUAGE_H_
+
+#include <string>
+
+namespace i18n {
+namespace addressinput {
+
+class Rule;
+
+// Helper for working with a BCP 47 language tag.
+// http://tools.ietf.org/html/bcp47
+struct Language {
+  explicit Language(const std::string& language_tag);
+  ~Language();
+
+  // The language tag (with '_' replaced with '-'), for example "zh-Latn-CN".
+  std::string tag;
+
+  // The base language, for example "zh". Always lowercase.
+  std::string base;
+
+  // True if the language tag explicitly has a Latin script. For example, this
+  // is true for "zh-Latn", but false for "zh". Only the second and third subtag
+  // positions are supported for script.
+  bool has_latin_script;
+};
+
+Language ChooseBestAddressLanguage(const Rule& address_region_rule,
+                                   const Language& ui_language);
+
+}  // namespace addressinput
+}  // namespace i18n
+
+#endif  // I18N_ADDRESSINPUT_LANGUAGE_H_