Override Date.prototype.to*String with Intl.DateTimeFormat.format

src/runtime/runtime-i18n.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 #ifdef V8_I18N_SUPPORT
 #include "src/runtime/runtime-utils.h"
 
 #include <memory>
 
@@ skipping 453 matching lines @@
                           reinterpret_cast<const uint16_t*>(field.getBuffer()),
                           field.length())),
       false);
 
   JSObject::AddProperty(element, factory->value_string(), value, NONE);
   RETURN_ON_EXCEPTION_VALUE(
       isolate, JSObject::AddDataElement(array, index, element, NONE), false);
   return true;
 }
 
+#if 0
+RUNTIME_FUNCTION(Runtime_UpdateTimezoneInDateFormat) {
+  HandleScope scope(isolate);
+
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, date_format_holder, 0);
+
+  // TODO(jshin): Updating the timezone of |date_format| everytime cached
+  // DateFormat is used is not optimal. date_format_holder can be
+  // changed to store DATE_CACHE_VERSION and update the timezone in
+  // |date_format| only when the stored DATE_CACHE_VERSION is different from
+  // the current DATE_CACHE_VERSION.
+  icu::SimpleDateFormat* date_format =
+      DateFormat::UnpackDateFormat(isolate, date_format_holder);
+  if (!date_format) return isolate->ThrowIllegalOperation();
+
+  date_format->adoptTimeZone(icu::TimeZone::createDefault());
+  return isolate->heap()->true_value();
+}
+#endif
+
 }  // namespace
 
 RUNTIME_FUNCTION(Runtime_InternalDateFormatToParts) {
   HandleScope scope(isolate);
   Factory* factory = isolate->factory();
 
   DCHECK(args.length() == 2);
 
   CONVERT_ARG_HANDLE_CHECKED(JSObject, date_format_holder, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSDate, date, 1);
@@ skipping 717 matching lines @@
   Handle<FixedArray> date_cache_version =
       Handle<FixedArray>::cast(isolate->eternal_handles()->GetSingleton(
           EternalHandles::DATE_CACHE_VERSION));
   return date_cache_version->get(0);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_I18N_SUPPORT