Revert "[intl] Return "UTC" instead of "Etc/UTC" or "Etc/GMT" as DefaultTimeZone"

This reverts commit 6b682148.

Reason for revert: Cause CHECK violation in https://bugs.chromium.org/p/chromium/issues/detail?id=1356838 
Original change's description:
> [intl] Return "UTC" instead of "Etc/UTC" or "Etc/GMT" as DefaultTimeZone
>
> Refactoring the code dealing with TimeZone Canonicalization.
> Change CanonicalizeTimeZoneName from return MaybeHandle<String> to Handle<String>
> Move TimeZoneId from JSDateTimeFormat to Intl and return Handle<String> instead of Handle<Object>
>
>
> Bug: v8:13112
> Change-Id: I678b0e0d407e5e4e9dd8b7120c0e99e7e2d9c5ea
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3833435
> Reviewed-by: Shu-yu Guo <syg@chromium.org>
> Commit-Queue: Frank Tang <ftang@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#82505}

Bug: v8:13112
Change-Id: If4df4bc19b5d1a02c51e2c944abaca8a25b76a1e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3863883Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#82796}

src/objects/intl-objects.cc

@@ -2819,37 +2819,21 @@ bool IsUnicodeStringValidTimeZoneName(const icu::UnicodeString& id) {
 }
 }  // namespace
 
-Handle<String> Intl::CanonicalizeTimeZoneID(Isolate* isolate,
-                                            const icu::UnicodeString& id) {
+MaybeHandle<String> Intl::CanonicalizeTimeZoneName(Isolate* isolate,
+                                                   Handle<String> identifier) {
   UErrorCode status = U_ZERO_ERROR;
+  std::string time_zone =
+      JSDateTimeFormat::CanonicalizeTimeZoneID(identifier->ToCString().get());
+  icu::UnicodeString time_zone_ustring =
+      icu::UnicodeString(time_zone.c_str(), -1, US_INV);
   icu::UnicodeString canonical;
-  icu::TimeZone::getCanonicalID(id, canonical, status);
+  icu::TimeZone::getCanonicalID(time_zone_ustring, canonical, status);
   CHECK(U_SUCCESS(status));
-  // In CLDR (http://unicode.org/cldr/trac/ticket/9943), Etc/UTC is made
-  // a separate timezone ID from Etc/GMT even though they're still the same
-  // timezone. We have Etc/UTC because 'UTC', 'Etc/Universal',
-  // 'Etc/Zulu' and others are turned to 'Etc/UTC' by ICU. Etc/GMT comes
-  // from Etc/GMT0, Etc/GMT+0, Etc/GMT-0, Etc/Greenwich.
-  // ecma402#sec-canonicalizetimezonename step 3
   if (canonical == UNICODE_STRING_SIMPLE("Etc/UTC") ||
       canonical == UNICODE_STRING_SIMPLE("Etc/GMT")) {
     return isolate->factory()->UTC_string();
   }
-  return Intl::ToString(isolate, canonical).ToHandleChecked();
-}
-
-Handle<String> Intl::CanonicalizeTimeZoneName(Isolate* isolate,
-                                              Handle<String> identifier) {
-  std::string time_zone =
-      JSDateTimeFormat::CanonicalizeTimeZoneID(identifier->ToCString().get());
-  return CanonicalizeTimeZoneID(
-      isolate, icu::UnicodeString(time_zone.c_str(), -1, US_INV));
-}
-
-Handle<String> Intl::TimeZoneId(Isolate* isolate, const icu::TimeZone& tz) {
-  icu::UnicodeString time_zone;
-  tz.getID(time_zone);
-  return Intl::CanonicalizeTimeZoneID(isolate, time_zone);
+  return Intl::ToString(isolate, canonical);
 }
 
 bool Intl::IsValidTimeZoneName(Isolate* isolate, Handle<String> id) {
@@ -2958,8 +2942,16 @@ Handle<String> Intl::SourceString(Isolate* isolate, FormatRangeSource source) {
 }
 
 Handle<String> Intl::DefaultTimeZone(Isolate* isolate) {
-  std::unique_ptr<icu::TimeZone> tz(icu::TimeZone::createDefault());
-  return TimeZoneId(isolate, *tz);
+  icu::UnicodeString id;
+  {
+    std::unique_ptr<icu::TimeZone> tz(icu::TimeZone::createDefault());
+    tz->getID(id);
+  }
+  UErrorCode status = U_ZERO_ERROR;
+  icu::UnicodeString canonical;
+  icu::TimeZone::getCanonicalID(id, canonical, status);
+  DCHECK(U_SUCCESS(status));
+  return Intl::ToString(isolate, canonical).ToHandleChecked();
 }
 
 namespace {

src/objects/intl-objects.h

@@ -390,13 +390,8 @@ class Intl {
   static std::vector<int64_t> GetTimeZonePossibleOffsetMilliseconds(
       Isolate* isolate, int32_t time_zone_index, int64_t time_ms);
 
-  static Handle<String> CanonicalizeTimeZoneName(Isolate* isolate,
-                                                 Handle<String> identifier);
-
-  static Handle<String> CanonicalizeTimeZoneID(
-      Isolate* isolate, const icu::UnicodeString& identifier);
-
-  static Handle<String> TimeZoneId(Isolate* isolate, const icu::TimeZone& tz);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<String> CanonicalizeTimeZoneName(
+      Isolate* isolate, Handle<String> identifier);
 
   // ecma402/#sec-coerceoptionstoobject
   V8_WARN_UNUSED_RESULT static MaybeHandle<JSReceiver> CoerceOptionsToObject(

src/objects/js-date-time-format.cc

@@ -495,6 +495,37 @@ int FractionalSecondDigitsFromPattern(const std::string& pattern) {
 
 }  // namespace
 
+Handle<Object> JSDateTimeFormat::TimeZoneId(Isolate* isolate,
+                                            const icu::TimeZone& tz) {
+  Factory* factory = isolate->factory();
+  icu::UnicodeString time_zone;
+  tz.getID(time_zone);
+  UErrorCode status = U_ZERO_ERROR;
+  icu::UnicodeString canonical_time_zone;
+  icu::TimeZone::getCanonicalID(time_zone, canonical_time_zone, status);
+  Handle<Object> timezone_value;
+  if (U_SUCCESS(status)) {
+    // In CLDR (http://unicode.org/cldr/trac/ticket/9943), Etc/UTC is made
+    // a separate timezone ID from Etc/GMT even though they're still the same
+    // timezone. We have Etc/UTC because 'UTC', 'Etc/Universal',
+    // 'Etc/Zulu' and others are turned to 'Etc/UTC' by ICU. Etc/GMT comes
+    // from Etc/GMT0, Etc/GMT+0, Etc/GMT-0, Etc/Greenwich.
+    // ecma402#sec-canonicalizetimezonename step 3
+    if (canonical_time_zone == UNICODE_STRING_SIMPLE("Etc/UTC") ||
+        canonical_time_zone == UNICODE_STRING_SIMPLE("Etc/GMT")) {
+      timezone_value = factory->UTC_string();
+    } else {
+      ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+          isolate, timezone_value, Intl::ToString(isolate, canonical_time_zone),
+          Handle<Object>());
+    }
+  } else {
+    // Somehow on Windows we will reach here.
+    timezone_value = factory->undefined_value();
+  }
+  return timezone_value;
+}
+
 namespace {
 Handle<String> GetCalendar(Isolate* isolate,
                            const icu::SimpleDateFormat& simple_date_format,
@@ -526,8 +557,8 @@ Handle<String> GetCalendar(Isolate* isolate,
 
 Handle<Object> GetTimeZone(Isolate* isolate,
                            const icu::SimpleDateFormat& simple_date_format) {
-  return Intl::TimeZoneId(isolate,
-                          simple_date_format.getCalendar()->getTimeZone());
+  return JSDateTimeFormat::TimeZoneId(
+      isolate, simple_date_format.getCalendar()->getTimeZone());
 }
 }  // namespace
 

src/objects/js-date-time-format.h

@@ -99,6 +99,7 @@ class JSDateTimeFormat
 
   V8_EXPORT_PRIVATE static const std::set<std::string>& GetAvailableLocales();
 
+  Handle<Object> static TimeZoneId(Isolate* isolate, const icu::TimeZone& tz);
   std::unique_ptr<icu::TimeZone> static CreateTimeZone(const char* timezone);
 
   V8_EXPORT_PRIVATE static std::string CanonicalizeTimeZoneID(

src/objects/js-temporal-objects.cc

@@ -4591,7 +4591,7 @@ bool IsValidTimeZoneName(Isolate* isolate, Handle<String> time_zone) {
 
 Handle<String> CanonicalizeTimeZoneName(Isolate* isolate,
                                         Handle<String> identifier) {
-  return Intl::CanonicalizeTimeZoneName(isolate, identifier);
+  return Intl::CanonicalizeTimeZoneName(isolate, identifier).ToHandleChecked();
 }
 
 #else   // V8_INTL_SUPPORT