Add a timezone utility file to base/.

Currently there's just one function exported, which checks the system timezone and returns a 2-character ASCII country code for it.

BUG=303368

Review URL: https://codereview.chromium.org/26315008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235823 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 657 insertions, 0 deletions

diff --git a/base/base.gyp b/base/base.gyp
index fb096b9..dc10118 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -347,6 +347,8 @@
         'i18n/string_search.h',
         'i18n/time_formatting.cc',
         'i18n/time_formatting.h',
+        'i18n/timezone.cc',
+        'i18n/timezone.h',
       ],
     },
     {
@@ -529,6 +531,7 @@
         'i18n/rtl_unittest.cc',
         'i18n/string_search_unittest.cc',
         'i18n/time_formatting_unittest.cc',
+        'i18n/timezone_unittest.cc',
         'ini_parser_unittest.cc',
         'ios/device_util_unittest.mm',
         'json/json_parser_unittest.cc',
diff --git a/base/i18n/timezone.cc b/base/i18n/timezone.cc
new file mode 100644
index 0000000..8c65279
--- /dev/null
+++ b/base/i18n/timezone.cc
@@ -0,0 +1,608 @@
+// 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.
+
+#include "base/i18n/timezone.h"
+
+#include <map>
+
+#include "base/memory/singleton.h"
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "third_party/icu/source/i18n/unicode/timezone.h"
+
+namespace base {
+
+namespace {
+
+class TimezoneMap {
+ public:
+  static TimezoneMap* GetInstance() {
+    return Singleton<TimezoneMap>::get();
+  }
+
+  std::string CountryCodeForTimezone(const std::string& olson_code) {
+    std::map<std::string, std::string>::iterator iter = map_.find(olson_code);
+    if (iter != map_.end())
+      return iter->second;
+
+    return std::string();
+  }
+
+ private:
+  TimezoneMap() {
+    // These mappings are adapted from zone.tab, which is available at
+    // <http://www.ietf.org/timezones/data/zone.tab> and is a part of public
+    // domain.
+    struct OlsonCodeData {
+      std::string country_code;
+      std::string olson_code;
+    } olson_code_data[] = {
+        { "AD", "Europe/Andorra" },
+        { "AE", "Asia/Dubai" },
+        { "AF", "Asia/Kabul" },
+        { "AG", "America/Antigua" },
+        { "AI", "America/Anguilla" },
+        { "AL", "Europe/Tirane" },
+        { "AM", "Asia/Yerevan" },
+        { "AO", "Africa/Luanda" },
+        { "AQ", "Antarctica/McMurdo" },
+        { "AQ", "Antarctica/Rothera" },
+        { "AQ", "Antarctica/Palmer" },
+        { "AQ", "Antarctica/Mawson" },
+        { "AQ", "Antarctica/Davis" },
+        { "AQ", "Antarctica/Casey" },
+        { "AQ", "Antarctica/Vostok" },
+        { "AQ", "Antarctica/DumontDUrville" },
+        { "AQ", "Antarctica/Syowa" },
+        { "AR", "America/Argentina/Buenos_Aires" },
+        { "AR", "America/Argentina/Cordoba" },
+        { "AR", "America/Argentina/Salta" },
+        { "AR", "America/Argentina/Jujuy" },
+        { "AR", "America/Argentina/Tucuman" },
+        { "AR", "America/Argentina/Catamarca" },
+        { "AR", "America/Argentina/La_Rioja" },
+        { "AR", "America/Argentina/San_Juan" },
+        { "AR", "America/Argentina/Mendoza" },
+        { "AR", "America/Argentina/San_Luis" },
+        { "AR", "America/Argentina/Rio_Gallegos" },
+        { "AR", "America/Argentina/Ushuaia" },
+        { "AS", "Pacific/Pago_Pago" },
+        { "AT", "Europe/Vienna" },
+        { "AU", "Australia/Lord_Howe" },
+        { "AU", "Antarctica/Macquarie" },
+        { "AU", "Australia/Hobart" },
+        { "AU", "Australia/Currie" },
+        { "AU", "Australia/Melbourne" },
+        { "AU", "Australia/Sydney" },
+        { "AU", "Australia/Broken_Hill" },
+        { "AU", "Australia/Brisbane" },
+        { "AU", "Australia/Lindeman" },
+        { "AU", "Australia/Adelaide" },
+        { "AU", "Australia/Darwin" },
+        { "AU", "Australia/Perth" },
+        { "AU", "Australia/Eucla" },
+        { "AW", "America/Aruba" },
+        { "AX", "Europe/Mariehamn" },
+        { "AZ", "Asia/Baku" },
+        { "BA", "Europe/Sarajevo" },
+        { "BB", "America/Barbados" },
+        { "BD", "Asia/Dhaka" },
+        { "BE", "Europe/Brussels" },
+        { "BF", "Africa/Ouagadougou" },
+        { "BG", "Europe/Sofia" },
+        { "BH", "Asia/Bahrain" },
+        { "BI", "Africa/Bujumbura" },
+        { "BJ", "Africa/Porto-Novo" },
+        { "BL", "America/St_Barthelemy" },
+        { "BM", "Atlantic/Bermuda" },
+        { "BN", "Asia/Brunei" },
+        { "BO", "America/La_Paz" },
+        { "BQ", "America/Kralendijk" },
+        { "BR", "America/Noronha" },
+        { "BR", "America/Belem" },
+        { "BR", "America/Fortaleza" },
+        { "BR", "America/Recife" },
+        { "BR", "America/Araguaina" },
+        { "BR", "America/Maceio" },
+        { "BR", "America/Bahia" },
+        { "BR", "America/Sao_Paulo" },
+        { "BR", "America/Campo_Grande" },
+        { "BR", "America/Cuiaba" },
+        { "BR", "America/Santarem" },
+        { "BR", "America/Porto_Velho" },
+        { "BR", "America/Boa_Vista" },
+        { "BR", "America/Manaus" },
+        { "BR", "America/Eirunepe" },
+        { "BR", "America/Rio_Branco" },
+        { "BS", "America/Nassau" },
+        { "BT", "Asia/Thimphu" },
+        { "BW", "Africa/Gaborone" },
+        { "BY", "Europe/Minsk" },
+        { "BZ", "America/Belize" },
+        { "CA", "America/St_Johns" },
+        { "CA", "America/Halifax" },
+        { "CA", "America/Glace_Bay" },
+        { "CA", "America/Moncton" },
+        { "CA", "America/Goose_Bay" },
+        { "CA", "America/Blanc-Sablon" },
+        { "CA", "America/Toronto" },
+        { "CA", "America/Nipigon" },
+        { "CA", "America/Thunder_Bay" },
+        { "CA", "America/Iqaluit" },
+        { "CA", "America/Pangnirtung" },
+        { "CA", "America/Resolute" },
+        { "CA", "America/Atikokan" },
+        { "CA", "America/Rankin_Inlet" },
+        { "CA", "America/Winnipeg" },
+        { "CA", "America/Rainy_River" },
+        { "CA", "America/Regina" },
+        { "CA", "America/Swift_Current" },
+        { "CA", "America/Edmonton" },
+        { "CA", "America/Cambridge_Bay" },
+        { "CA", "America/Yellowknife" },
+        { "CA", "America/Inuvik" },
+        { "CA", "America/Creston" },
+        { "CA", "America/Dawson_Creek" },
+        { "CA", "America/Vancouver" },
+        { "CA", "America/Whitehorse" },
+        { "CA", "America/Dawson" },
+        { "CC", "Indian/Cocos" },
+        { "CD", "Africa/Kinshasa" },
+        { "CD", "Africa/Lubumbashi" },
+        { "CF", "Africa/Bangui" },
+        { "CG", "Africa/Brazzaville" },
+        { "CH", "Europe/Zurich" },
+        { "CI", "Africa/Abidjan" },
+        { "CK", "Pacific/Rarotonga" },
+        { "CL", "America/Santiago" },
+        { "CL", "Pacific/Easter" },
+        { "CM", "Africa/Douala" },
+        { "CN", "Asia/Shanghai" },
+        { "CN", "Asia/Harbin" },
+        { "CN", "Asia/Chongqing" },
+        { "CN", "Asia/Urumqi" },
+        { "CN", "Asia/Kashgar" },
+        { "CO", "America/Bogota" },
+        { "CR", "America/Costa_Rica" },
+        { "CU", "America/Havana" },
+        { "CV", "Atlantic/Cape_Verde" },
+        { "CW", "America/Curacao" },
+        { "CX", "Indian/Christmas" },
+        { "CY", "Asia/Nicosia" },
+        { "CZ", "Europe/Prague" },
+        { "DE", "Europe/Berlin" },
+        { "DE", "Europe/Busingen" },
+        { "DJ", "Africa/Djibouti" },
+        { "DK", "Europe/Copenhagen" },
+        { "DM", "America/Dominica" },
+        { "DO", "America/Santo_Domingo" },
+        { "DZ", "Africa/Algiers" },
+        { "EC", "America/Guayaquil" },
+        { "EC", "Pacific/Galapagos" },
+        { "EE", "Europe/Tallinn" },
+        { "EG", "Africa/Cairo" },
+        { "EH", "Africa/El_Aaiun" },
+        { "ER", "Africa/Asmara" },
+        { "ES", "Europe/Madrid" },
+        { "ES", "Africa/Ceuta" },
+        { "ES", "Atlantic/Canary" },
+        { "ET", "Africa/Addis_Ababa" },
+        { "FI", "Europe/Helsinki" },
+        { "FJ", "Pacific/Fiji" },
+        { "FK", "Atlantic/Stanley" },
+        { "FM", "Pacific/Chuuk" },
+        { "FM", "Pacific/Pohnpei" },
+        { "FM", "Pacific/Kosrae" },
+        { "FO", "Atlantic/Faroe" },
+        { "FR", "Europe/Paris" },
+        { "GA", "Africa/Libreville" },
+        { "GB", "Europe/London" },
+        { "GD", "America/Grenada" },
+        { "GE", "Asia/Tbilisi" },
+        { "GF", "America/Cayenne" },
+        { "GG", "Europe/Guernsey" },
+        { "GH", "Africa/Accra" },
+        { "GI", "Europe/Gibraltar" },
+        { "GL", "America/Godthab" },
+        { "GL", "America/Danmarkshavn" },
+        { "GL", "America/Scoresbysund" },
+        { "GL", "America/Thule" },
+        { "GM", "Africa/Banjul" },
+        { "GN", "Africa/Conakry" },
+        { "GP", "America/Guadeloupe" },
+        { "GQ", "Africa/Malabo" },
+        { "GR", "Europe/Athens" },
+        { "GS", "Atlantic/South_Georgia" },
+        { "GT", "America/Guatemala" },
+        { "GU", "Pacific/Guam" },
+        { "GW", "Africa/Bissau" },
+        { "GY", "America/Guyana" },
+        { "HK", "Asia/Hong_Kong" },
+        { "HN", "America/Tegucigalpa" },
+        { "HR", "Europe/Zagreb" },
+        { "HT", "America/Port-au-Prince" },
+        { "HU", "Europe/Budapest" },
+        { "ID", "Asia/Jakarta" },
+        { "ID", "Asia/Pontianak" },
+        { "ID", "Asia/Makassar" },
+        { "ID", "Asia/Jayapura" },
+        { "IE", "Europe/Dublin" },
+        { "IL", "Asia/Jerusalem" },
+        { "IM", "Europe/Isle_of_Man" },
+        { "IN", "Asia/Kolkata" },
+        { "IO", "Indian/Chagos" },
+        { "IQ", "Asia/Baghdad" },
+        { "IR", "Asia/Tehran" },
+        { "IS", "Atlantic/Reykjavik" },
+        { "IT", "Europe/Rome" },
+        { "JE", "Europe/Jersey" },
+        { "JM", "America/Jamaica" },
+        { "JO", "Asia/Amman" },
+        { "JP", "Asia/Tokyo" },
+        { "KE", "Africa/Nairobi" },
+        { "KG", "Asia/Bishkek" },
+        { "KH", "Asia/Phnom_Penh" },
+        { "KI", "Pacific/Tarawa" },
+        { "KI", "Pacific/Enderbury" },
+        { "KI", "Pacific/Kiritimati" },
+        { "KM", "Indian/Comoro" },
+        { "KN", "America/St_Kitts" },
+        { "KP", "Asia/Pyongyang" },
+        { "KR", "Asia/Seoul" },
+        { "KW", "Asia/Kuwait" },
+        { "KY", "America/Cayman" },
+        { "KZ", "Asia/Almaty" },
+        { "KZ", "Asia/Qyzylorda" },
+        { "KZ", "Asia/Aqtobe" },
+        { "KZ", "Asia/Aqtau" },
+        { "KZ", "Asia/Oral" },
+        { "LA", "Asia/Vientiane" },
+        { "LB", "Asia/Beirut" },
+        { "LC", "America/St_Lucia" },
+        { "LI", "Europe/Vaduz" },
+        { "LK", "Asia/Colombo" },
+        { "LR", "Africa/Monrovia" },
+        { "LS", "Africa/Maseru" },
+        { "LT", "Europe/Vilnius" },
+        { "LU", "Europe/Luxembourg" },
+        { "LV", "Europe/Riga" },
+        { "LY", "Africa/Tripoli" },
+        { "MA", "Africa/Casablanca" },
+        { "MC", "Europe/Monaco" },
+        { "MD", "Europe/Chisinau" },
+        { "ME", "Europe/Podgorica" },
+        { "MF", "America/Marigot" },
+        { "MG", "Indian/Antananarivo" },
+        { "MH", "Pacific/Majuro" },
+        { "MH", "Pacific/Kwajalein" },
+        { "MK", "Europe/Skopje" },
+        { "ML", "Africa/Bamako" },
+        { "MM", "Asia/Rangoon" },
+        { "MN", "Asia/Ulaanbaatar" },
+        { "MN", "Asia/Hovd" },
+        { "MN", "Asia/Choibalsan" },
+        { "MO", "Asia/Macau" },
+        { "MP", "Pacific/Saipan" },
+        { "MQ", "America/Martinique" },
+        { "MR", "Africa/Nouakchott" },
+        { "MS", "America/Montserrat" },
+        { "MT", "Europe/Malta" },
+        { "MU", "Indian/Mauritius" },
+        { "MV", "Indian/Maldives" },
+        { "MW", "Africa/Blantyre" },
+        { "MX", "America/Mexico_City" },
+        { "MX", "America/Cancun" },
+        { "MX", "America/Merida" },
+        { "MX", "America/Monterrey" },
+        { "MX", "America/Matamoros" },
+        { "MX", "America/Mazatlan" },
+        { "MX", "America/Chihuahua" },
+        { "MX", "America/Ojinaga" },
+        { "MX", "America/Hermosillo" },
+        { "MX", "America/Tijuana" },
+        { "MX", "America/Santa_Isabel" },
+        { "MX", "America/Bahia_Banderas" },
+        { "MY", "Asia/Kuala_Lumpur" },
+        { "MY", "Asia/Kuching" },
+        { "MZ", "Africa/Maputo" },
+        { "NA", "Africa/Windhoek" },
+        { "NC", "Pacific/Noumea" },
+        { "NE", "Africa/Niamey" },
+        { "NF", "Pacific/Norfolk" },
+        { "NG", "Africa/Lagos" },
+        { "NI", "America/Managua" },
+        { "NL", "Europe/Amsterdam" },
+        { "NO", "Europe/Oslo" },
+        { "NP", "Asia/Kathmandu" },
+        { "NR", "Pacific/Nauru" },
+        { "NU", "Pacific/Niue" },
+        { "NZ", "Pacific/Auckland" },
+        { "NZ", "Pacific/Chatham" },
+        { "OM", "Asia/Muscat" },
+        { "PA", "America/Panama" },
+        { "PE", "America/Lima" },
+        { "PF", "Pacific/Tahiti" },
+        { "PF", "Pacific/Marquesas" },
+        { "PF", "Pacific/Gambier" },
+        { "PG", "Pacific/Port_Moresby" },
+        { "PH", "Asia/Manila" },
+        { "PK", "Asia/Karachi" },
+        { "PL", "Europe/Warsaw" },
+        { "PM", "America/Miquelon" },
+        { "PN", "Pacific/Pitcairn" },
+        { "PR", "America/Puerto_Rico" },
+        { "PS", "Asia/Gaza" },
+        { "PS", "Asia/Hebron" },
+        { "PT", "Europe/Lisbon" },
+        { "PT", "Atlantic/Madeira" },
+        { "PT", "Atlantic/Azores" },
+        { "PW", "Pacific/Palau" },
+        { "PY", "America/Asuncion" },
+        { "QA", "Asia/Qatar" },
+        { "RE", "Indian/Reunion" },
+        { "RO", "Europe/Bucharest" },
+        { "RS", "Europe/Belgrade" },
+        { "RU", "Europe/Kaliningrad" },
+        { "RU", "Europe/Moscow" },
+        { "RU", "Europe/Volgograd" },
+        { "RU", "Europe/Samara" },
+        { "RU", "Asia/Yekaterinburg" },
+        { "RU", "Asia/Omsk" },
+        { "RU", "Asia/Novosibirsk" },
+        { "RU", "Asia/Novokuznetsk" },
+        { "RU", "Asia/Krasnoyarsk" },
+        { "RU", "Asia/Irkutsk" },
+        { "RU", "Asia/Yakutsk" },
+        { "RU", "Asia/Khandyga" },
+        { "RU", "Asia/Vladivostok" },
+        { "RU", "Asia/Sakhalin" },
+        { "RU", "Asia/Ust-Nera" },
+        { "RU", "Asia/Magadan" },
+        { "RU", "Asia/Kamchatka" },
+        { "RU", "Asia/Anadyr" },
+        { "RW", "Africa/Kigali" },
+        { "SA", "Asia/Riyadh" },
+        { "SB", "Pacific/Guadalcanal" },
+        { "SC", "Indian/Mahe" },
+        { "SD", "Africa/Khartoum" },
+        { "SE", "Europe/Stockholm" },
+        { "SG", "Asia/Singapore" },
+        { "SH", "Atlantic/St_Helena" },
+        { "SI", "Europe/Ljubljana" },
+        { "SJ", "Arctic/Longyearbyen" },
+        { "SK", "Europe/Bratislava" },
+        { "SL", "Africa/Freetown" },
+        { "SM", "Europe/San_Marino" },
+        { "SN", "Africa/Dakar" },
+        { "SO", "Africa/Mogadishu" },
+        { "SR", "America/Paramaribo" },
+        { "SS", "Africa/Juba" },
+        { "ST", "Africa/Sao_Tome" },
+        { "SV", "America/El_Salvador" },
+        { "SX", "America/Lower_Princes" },
+        { "SY", "Asia/Damascus" },
+        { "SZ", "Africa/Mbabane" },
+        { "TC", "America/Grand_Turk" },
+        { "TD", "Africa/Ndjamena" },
+        { "TF", "Indian/Kerguelen" },
+        { "TG", "Africa/Lome" },
+        { "TH", "Asia/Bangkok" },
+        { "TJ", "Asia/Dushanbe" },
+        { "TK", "Pacific/Fakaofo" },
+        { "TL", "Asia/Dili" },
+        { "TM", "Asia/Ashgabat" },
+        { "TN", "Africa/Tunis" },
+        { "TO", "Pacific/Tongatapu" },
+        { "TR", "Europe/Istanbul" },
+        { "TT", "America/Port_of_Spain" },
+        { "TV", "Pacific/Funafuti" },
+        { "TW", "Asia/Taipei" },
+        { "TZ", "Africa/Dar_es_Salaam" },
+        { "UA", "Europe/Kiev" },
+        { "UA", "Europe/Uzhgorod" },
+        { "UA", "Europe/Zaporozhye" },
+        { "UA", "Europe/Simferopol" },
+        { "UG", "Africa/Kampala" },
+        { "UM", "Pacific/Johnston" },
+        { "UM", "Pacific/Midway" },
+        { "UM", "Pacific/Wake" },
+        { "US", "America/New_York" },
+        { "US", "America/Detroit" },
+        { "US", "America/Kentucky/Louisville" },
+        { "US", "America/Kentucky/Monticello" },
+        { "US", "America/Indiana/Indianapolis" },
+        { "US", "America/Indiana/Vincennes" },
+        { "US", "America/Indiana/Winamac" },
+        { "US", "America/Indiana/Marengo" },
+        { "US", "America/Indiana/Petersburg" },
+        { "US", "America/Indiana/Vevay" },
+        { "US", "America/Chicago" },
+        { "US", "America/Indiana/Tell_City" },
+        { "US", "America/Indiana/Knox" },
+        { "US", "America/Menominee" },
+        { "US", "America/North_Dakota/Center" },
+        { "US", "America/North_Dakota/New_Salem" },
+        { "US", "America/North_Dakota/Beulah" },
+        { "US", "America/Denver" },
+        { "US", "America/Boise" },
+        { "US", "America/Phoenix" },
+        { "US", "America/Los_Angeles" },
+        { "US", "America/Anchorage" },
+        { "US", "America/Juneau" },
+        { "US", "America/Sitka" },
+        { "US", "America/Yakutat" },
+        { "US", "America/Nome" },
+        { "US", "America/Adak" },
+        { "US", "America/Metlakatla" },
+        { "US", "Pacific/Honolulu" },
+        { "UY", "America/Montevideo" },
+        { "UZ", "Asia/Samarkand" },
+        { "UZ", "Asia/Tashkent" },
+        { "VA", "Europe/Vatican" },
+        { "VC", "America/St_Vincent" },
+        { "VE", "America/Caracas" },
+        { "VG", "America/Tortola" },
+        { "VI", "America/St_Thomas" },
+        { "VN", "Asia/Ho_Chi_Minh" },
+        { "VU", "Pacific/Efate" },
+        { "WF", "Pacific/Wallis" },
+        { "WS", "Pacific/Apia" },
+        { "YE", "Asia/Aden" },
+        { "YT", "Indian/Mayotte" },
+        { "ZA", "Africa/Johannesburg" },
+        { "ZM", "Africa/Lusaka" },
+        { "ZW", "Africa/Harare" },
+        // The mappings below are custom additions to zone.tab.
+        { "GB", "Etc/GMT" },
+        { "GB", "Etc/UTC" },
+        { "GB", "Etc/UCT" },
+    };
+
+    for (size_t i = 0; i < ARRAYSIZE_UNSAFE(olson_code_data); ++i) {
+      map_[olson_code_data[i].olson_code] = olson_code_data[i].country_code;
+    }
+
+    // These are mapping from old codenames to new codenames. They are also
+    // part of public domain, and available at
+    // <http://www.ietf.org/timezones/data/backward>.
+    struct LinkData {
+      std::string old_code;
+      std::string new_code;
+    } link_data[] = {
+        { "Africa/Asmera", "Africa/Asmara" },
+        { "Africa/Timbuktu", "Africa/Bamako" },
+        { "America/Argentina/ComodRivadavia", "America/Argentina/Catamarca" },
+        { "America/Atka", "America/Adak" },
+        { "America/Buenos_Aires", "America/Argentina/Buenos_Aires" },
+        { "America/Catamarca", "America/Argentina/Catamarca" },
+        { "America/Coral_Harbour", "America/Atikokan" },
+        { "America/Cordoba", "America/Argentina/Cordoba" },
+        { "America/Ensenada", "America/Tijuana" },
+        { "America/Fort_Wayne", "America/Indiana/Indianapolis" },
+        { "America/Indianapolis", "America/Indiana/Indianapolis" },
+        { "America/Jujuy", "America/Argentina/Jujuy" },
+        { "America/Knox_IN", "America/Indiana/Knox" },
+        { "America/Louisville", "America/Kentucky/Louisville" },
+        { "America/Mendoza", "America/Argentina/Mendoza" },
+        { "America/Porto_Acre", "America/Rio_Branco" },
+        { "America/Rosario", "America/Argentina/Cordoba" },
+        { "America/Virgin", "America/St_Thomas" },
+        { "Asia/Ashkhabad", "Asia/Ashgabat" },
+        { "Asia/Chungking", "Asia/Chongqing" },
+        { "Asia/Dacca", "Asia/Dhaka" },
+        { "Asia/Katmandu", "Asia/Kathmandu" },
+        { "Asia/Calcutta", "Asia/Kolkata" },
+        { "Asia/Macao", "Asia/Macau" },
+        { "Asia/Tel_Aviv", "Asia/Jerusalem" },
+        { "Asia/Saigon", "Asia/Ho_Chi_Minh" },
+        { "Asia/Thimbu", "Asia/Thimphu" },
+        { "Asia/Ujung_Pandang", "Asia/Makassar" },
+        { "Asia/Ulan_Bator", "Asia/Ulaanbaatar" },
+        { "Atlantic/Faeroe", "Atlantic/Faroe" },
+        { "Atlantic/Jan_Mayen", "Europe/Oslo" },
+        { "Australia/ACT", "Australia/Sydney" },
+        { "Australia/Canberra", "Australia/Sydney" },
+        { "Australia/LHI", "Australia/Lord_Howe" },
+        { "Australia/NSW", "Australia/Sydney" },
+        { "Australia/North", "Australia/Darwin" },
+        { "Australia/Queensland", "Australia/Brisbane" },
+        { "Australia/South", "Australia/Adelaide" },
+        { "Australia/Tasmania", "Australia/Hobart" },
+        { "Australia/Victoria", "Australia/Melbourne" },
+        { "Australia/West", "Australia/Perth" },
+        { "Australia/Yancowinna", "Australia/Broken_Hill" },
+        { "Brazil/Acre", "America/Rio_Branco" },
+        { "Brazil/DeNoronha", "America/Noronha" },
+        { "Brazil/East", "America/Sao_Paulo" },
+        { "Brazil/West", "America/Manaus" },
+        { "Canada/Atlantic", "America/Halifax" },
+        { "Canada/Central", "America/Winnipeg" },
+        { "Canada/East-Saskatchewan", "America/Regina" },
+        { "Canada/Eastern", "America/Toronto" },
+        { "Canada/Mountain", "America/Edmonton" },
+        { "Canada/Newfoundland", "America/St_Johns" },
+        { "Canada/Pacific", "America/Vancouver" },
+        { "Canada/Saskatchewan", "America/Regina" },
+        { "Canada/Yukon", "America/Whitehorse" },
+        { "Chile/Continental", "America/Santiago" },
+        { "Chile/EasterIsland", "Pacific/Easter" },
+        { "Cuba", "America/Havana" },
+        { "Egypt", "Africa/Cairo" },
+        { "Eire", "Europe/Dublin" },
+        { "Europe/Belfast", "Europe/London" },
+        { "Europe/Tiraspol", "Europe/Chisinau" },
+        { "GB", "Europe/London" },
+        { "GB-Eire", "Europe/London" },
+        { "GMT+0", "Etc/GMT" },
+        { "GMT-0", "Etc/GMT" },
+        { "GMT0", "Etc/GMT" },
+        { "Greenwich", "Etc/GMT" },
+        { "Hongkong", "Asia/Hong_Kong" },
+        { "Iceland", "Atlantic/Reykjavik" },
+        { "Iran", "Asia/Tehran" },
+        { "Israel", "Asia/Jerusalem" },
+        { "Jamaica", "America/Jamaica" },
+        { "Japan", "Asia/Tokyo" },
+        { "Kwajalein", "Pacific/Kwajalein" },
+        { "Libya", "Africa/Tripoli" },
+        { "Mexico/BajaNorte", "America/Tijuana" },
+        { "Mexico/BajaSur", "America/Mazatlan" },
+        { "Mexico/General", "America/Mexico_City" },
+        { "NZ", "Pacific/Auckland" },
+        { "NZ-CHAT", "Pacific/Chatham" },
+        { "Navajo", "America/Denver" },
+        { "PRC", "Asia/Shanghai" },
+        { "Pacific/Samoa", "Pacific/Pago_Pago" },
+        { "Pacific/Yap", "Pacific/Chuuk" },
+        { "Pacific/Truk", "Pacific/Chuuk" },
+        { "Pacific/Ponape", "Pacific/Pohnpei" },
+        { "Poland", "Europe/Warsaw" },
+        { "Portugal", "Europe/Lisbon" },
+        { "ROC", "Asia/Taipei" },
+        { "ROK", "Asia/Seoul" },
+        { "Singapore", "Asia/Singapore" },
+        { "Turkey", "Europe/Istanbul" },
+        { "UCT", "Etc/UCT" },
+        { "US/Alaska", "America/Anchorage" },
+        { "US/Aleutian", "America/Adak" },
+        { "US/Arizona", "America/Phoenix" },
+        { "US/Central", "America/Chicago" },
+        { "US/East-Indiana", "America/Indiana/Indianapolis" },
+        { "US/Eastern", "America/New_York" },
+        { "US/Hawaii", "Pacific/Honolulu" },
+        { "US/Indiana-Starke", "America/Indiana/Knox" },
+        { "US/Michigan", "America/Detroit" },
+        { "US/Mountain", "America/Denver" },
+        { "US/Pacific", "America/Los_Angeles" },
+        { "US/Samoa", "Pacific/Pago_Pago" },
+        { "UTC", "Etc/UTC" },
+        { "Universal", "Etc/UTC" },
+        { "W-SU", "Europe/Moscow" },
+        { "Zulu", "Etc/UTC" },
+    };
+
+    for (size_t i = 0; i < ARRAYSIZE_UNSAFE(link_data); ++i) {
+      map_[link_data[i].old_code] = map_[link_data[i].new_code];
+    }
+  }
+
+  friend struct DefaultSingletonTraits<TimezoneMap>;
+
+  std::map<std::string, std::string> map_;
+
+  DISALLOW_COPY_AND_ASSIGN(TimezoneMap);
+};
+
+}  // namespace
+
+std::string CountryCodeForCurrentTimezone() {
+  scoped_ptr<icu::TimeZone> zone(icu::TimeZone::createDefault());
+  icu::UnicodeString id;
+  zone->getID(id);
+  string16 olson_code(id.getBuffer(), id.length());
+  return TimezoneMap::GetInstance()->CountryCodeForTimezone(
+      UTF16ToUTF8(olson_code));
+}
+
+}  // namespace base
diff --git a/base/i18n/timezone.h b/base/i18n/timezone.h
new file mode 100644
index 0000000..002538b
--- /dev/null
+++ b/base/i18n/timezone.h
@@ -0,0 +1,21 @@
+// 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 BASE_I18N_TIMEZONE_H_
+#define BASE_I18N_TIMEZONE_H_
+
+#include <string>
+
+#include "base/i18n/base_i18n_export.h"
+
+namespace base {
+
+// Checks the system timezone and turns it into a two-character ASCII country
+// code. If this fails for some reason (for example, it will always fail on
+// Android), it will return an empty string.
+BASE_I18N_EXPORT std::string CountryCodeForCurrentTimezone();
+
+}  // namespace base
+
+#endif  // BASE_TIME_TIMEZONE_H_
diff --git a/base/i18n/timezone_unittest.cc b/base/i18n/timezone_unittest.cc
new file mode 100644
index 0000000..0c73c01
--- /dev/null
+++ b/base/i18n/timezone_unittest.cc
@@ -0,0 +1,25 @@
+// 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.
+
+#include "base/i18n/timezone.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace {
+
+#if defined(OS_ANDROID)
+// icu's timezone utility doesn't work on Android.
+#define MAYBE_CountryCodeForCurrentTimezone DISABLED_CountryCodeForCurrentTimezone
+#else
+#define MAYBE_CountryCodeForCurrentTimezone CountryCodeForCurrentTimezone
+#endif
+
+TEST(TimezoneTest, MAYBE_CountryCodeForCurrentTimezone) {
+  std::string country_code = CountryCodeForCurrentTimezone();
+  EXPECT_EQ(2U, country_code.size());
+}
+
+}  // namespace
+}  // namespace base