Extend with a language code in http accept languages

chrome/browser/android/preferences/pref_service_bridge.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/android/preferences/pref_service_bridge.h"
 
 #include <jni.h>
 #include <stddef.h>
 
 #include <memory>
@@ skipping 1120 matching lines @@
 // language tags (BCP47 compliant format). Each language tag contains a language
 // code and a country code or a language code only.
 void PrefServiceBridge::PrependToAcceptLanguagesIfNecessary(
     const std::string& locales,
     std::string* accept_languages) {
   std::vector<std::string> locale_list =
       base::SplitString(locales + "," + *accept_languages, ",",
                         base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
 
   std::set<std::string> seen_tags;
-  std::vector<std::pair<std::string, std::string>> unique_locale_list;
+  std::vector<std::string> unique_locale_list;
   for (const std::string& locale_str : locale_list) {
     char locale_ID[ULOC_FULLNAME_CAPACITY] = {};
     char language_code_buffer[ULOC_LANG_CAPACITY] = {};
     char country_code_buffer[ULOC_COUNTRY_CAPACITY] = {};
 
     UErrorCode error = U_ZERO_ERROR;
     uloc_forLanguageTag(locale_str.c_str(), locale_ID, ULOC_FULLNAME_CAPACITY,
                         nullptr, &error);
     if (U_FAILURE(error)) {
       LOG(ERROR) << "Ignoring invalid locale representation " << locale_str;
@@ skipping 17 matching lines @@
     }
 
     std::string language_code(language_code_buffer);
     std::string country_code(country_code_buffer);
     std::string language_tag(language_code + "-" + country_code);
 
     if (seen_tags.find(language_tag) != seen_tags.end())
       continue;
 
     seen_tags.insert(language_tag);
-    unique_locale_list.push_back(std::make_pair(language_code, country_code));
+    if (!country_code.empty()) {
+      unique_locale_list.push_back(language_tag);
+    } else {
+      unique_locale_list.push_back(language_code);
+    }
   }
-
-  // If language is not in the accept languages list, also add language
-  // code. A language code should only be inserted after the last
-  // languageTag that contains that language.
-  // This will work with the IDS_ACCEPT_LANGUAGE localized strings bundled
-  // with Chrome but may fail on arbitrary lists of language tags due to
-  // differences in case and whitespace.
-  std::set<std::string> seen_languages;
-  std::vector<std::string> output_list;
-  for (auto it = unique_locale_list.rbegin(); it != unique_locale_list.rend();
-       ++it) {
-    if (seen_languages.find(it->first) == seen_languages.end()) {
-      output_list.push_back(it->first);
-      seen_languages.insert(it->first);
-    }
-    if (!it->second.empty())
-      output_list.push_back(it->first + "-" + it->second);
-  }
-
-  std::reverse(output_list.begin(), output_list.end());
-  *accept_languages = base::JoinString(output_list, ",");
+  *accept_languages = base::JoinString(unique_locale_list, ",");
 }
 
 // static
 std::string PrefServiceBridge::GetAndroidPermissionForContentSetting(
     ContentSettingsType content_type) {
   JNIEnv* env = AttachCurrentThread();
   base::android::ScopedJavaLocalRef<jstring> android_permission =
       Java_PrefServiceBridge_getAndroidPermissionForContentSetting(
           env, content_type);
   if (android_permission.is_null())
     return std::string();
 
   return ConvertJavaStringToUTF8(android_permission);
 }
 
 static void SetSupervisedUserId(JNIEnv* env,
                                 const JavaParamRef<jobject>& obj,
                                 const JavaParamRef<jstring>& pref) {
   GetPrefService()->SetString(prefs::kSupervisedUserId,
                               ConvertJavaStringToUTF8(env, pref));
 }