Migrate to use the new public getOffsetFromLocal method

This API is the new public one added in ICU 69.1
in https://github.com/unicode-org/icu/pull/1610

Bug: v8:11512
Change-Id: I424e15e6a60edee7c98e6ce55974986f0bb6ab1b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2876368
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74428}

src/objects/intl-objects.cc

@@ -2027,23 +2027,15 @@ icu::TimeZone* ICUTimezoneCache::GetTimeZone() {
 bool ICUTimezoneCache::GetOffsets(double time_ms, bool is_utc,
                                   int32_t* raw_offset, int32_t* dst_offset) {
   UErrorCode status = U_ZERO_ERROR;
-  // TODO(jshin): ICU TimeZone class handles skipped time differently from
-  // Ecma 262 (https://github.com/tc39/ecma262/pull/778) and icu::TimeZone
-  // class does not expose the necessary API. Fixing
-  // http://bugs.icu-project.org/trac/ticket/13268 would make it easy to
-  // implement the proposed spec change. A proposed fix for ICU is
-  //    https://chromium-review.googlesource.com/851265 .
-  // In the meantime, use an internal (still public) API of icu::BasicTimeZone.
-  // Once it's accepted by the upstream, get rid of cast. Note that casting
-  // TimeZone to BasicTimeZone is safe because we know that icu::TimeZone used
-  // here is a BasicTimeZone.
   if (is_utc) {
     GetTimeZone()->getOffset(time_ms, false, *raw_offset, *dst_offset, status);
   } else {
+    // Note that casting TimeZone to BasicTimeZone is safe because we know that
+    // icu::TimeZone used here is a BasicTimeZone.
     static_cast<const icu::BasicTimeZone*>(GetTimeZone())
-        ->getOffsetFromLocal(time_ms, icu::BasicTimeZone::kFormer,
-                             icu::BasicTimeZone::kFormer, *raw_offset,
-                             *dst_offset, status);
+        ->getOffsetFromLocal(time_ms, UCAL_TZ_LOCAL_FORMER,
+                             UCAL_TZ_LOCAL_FORMER, *raw_offset, *dst_offset,
+                             status);
   }
 
   return U_SUCCESS(status);

src/objects/intl-objects.h

@@ -21,7 +21,7 @@
 #include "unicode/locid.h"
 #include "unicode/uversion.h"
 
-#define V8_MINIMUM_ICU_VERSION 68
+#define V8_MINIMUM_ICU_VERSION 69
 
 namespace U_ICU_NAMESPACE {
 class BreakIterator;