Reland "Add test to show the crashing of TimeZone::AdoptDefault"

This is a reland of 91415227

Original change's description:
> Add test to show the crashing of TimeZone::AdoptDefault
> 
> The ICU DEPS for chromium is landing in
> https://chromium-review.googlesource.com/c/chromium/src/+/1607506
> 
> Bug: chromium:950851
> Change-Id: If16e82d70c319108ead06dd095b22ecda5408a6b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1601370
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Commit-Queue: Frank Tang <ftang@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61550}

Bug: chromium:950851
Change-Id: I427eba86bb5d4017a43b6767a1da4280d87297eb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1613896Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61565}

test/unittests/BUILD.gn

@@ -147,6 +147,7 @@ v8_source_set("unittests_sources") {
     "compiler/zone-stats-unittest.cc",
     "conversions-unittest.cc",
     "counters-unittest.cc",
+    "date-cache-unittest.cc",
     "detachable-vector-unittest.cc",
     "eh-frame-iterator-unittest.cc",
     "eh-frame-writer-unittest.cc",

test/unittests/date-cache-unittest.cc

+// Copyright 2019 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_INTL_SUPPORT
+#include "src/base/platform/platform.h"
+#include "src/date/date.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "unicode/strenum.h"
+#include "unicode/timezone.h"
+
+namespace v8 {
+namespace internal {
+
+// A recent time for the test.
+// 2019-05-08T04:16:04.845Z
+static const int64_t kStartTime = 1557288964845;
+
+class AdoptDefaultThread final : public base::Thread {
+ public:
+  AdoptDefaultThread() : base::Thread(Options("AdoptDefault")) {}
+
+  void Run() override {
+    printf("AdoptDefaultThread Start\n");
+    std::unique_ptr<icu::StringEnumeration> timezones(
+        icu::TimeZone::createEnumeration());
+    UErrorCode status = U_ZERO_ERROR;
+    const icu::UnicodeString* timezone = timezones->snext(status);
+    icu::TimeZone::adoptDefault(icu::TimeZone::createTimeZone(*timezone));
+    printf("AdoptDefaultThread End\n");
+  }
+};
+
+class GetLocalOffsetFromOSThread final : public base::Thread {
+ public:
+  explicit GetLocalOffsetFromOSThread(bool utc)
+      : base::Thread(Options("GetLocalOffsetFromOS")), utc_(utc) {}
+
+  void Run() override {
+    printf("GetLocalOffsetFromOSThread Start\n");
+    DateCache date_cache;
+    date_cache.GetLocalOffsetFromOS(kStartTime, utc_);
+    printf("GetLocalOffsetFromOSThread End\n");
+  }
+
+ private:
+  bool utc_;
+};
+
+class LocalTimezoneThread final : public base::Thread {
+ public:
+  LocalTimezoneThread() : base::Thread(Options("LocalTimezone")) {}
+
+  void Run() override {
+    printf("LocalTimezoneThread Start\n");
+    DateCache date_cache;
+    date_cache.LocalTimezone(kStartTime);
+    printf("LocalTimezoneThread End\n");
+  }
+};
+
+TEST(DateCache, AdoptDefaultFirst) {
+  AdoptDefaultThread t1;
+  GetLocalOffsetFromOSThread t2(true);
+  GetLocalOffsetFromOSThread t3(false);
+  LocalTimezoneThread t4;
+
+  // The AdoptDefaultFirst will always pass. Just a test to ensure
+  // our testing code itself is correct.
+  // We finish all the operation AdoptDefaultThread before
+  // running all other thread so it won't show the problem of
+  // AdoptDefault trashing newly create default.
+  t1.Start();
+  t1.Join();
+
+  t2.Start();
+  t3.Start();
+  t4.Start();
+
+  t2.Join();
+  t3.Join();
+  t4.Join();
+}
+
+TEST(DateCache, AdoptDefaultMixed) {
+  AdoptDefaultThread t1;
+  GetLocalOffsetFromOSThread t2(true);
+  GetLocalOffsetFromOSThread t3(false);
+  LocalTimezoneThread t4;
+
+  // The AdoptDefaultMixed run AdoptDefaultThread concurrently
+  // with other thread so if the AdoptDefault is not thread safe
+  // it will cause crash in other thread because the TimeZone
+  // newly created by createDefault could be trashed by AdoptDefault
+  // while a deleted DEFAULT_ZONE got cloned.
+  t1.Start();
+  t2.Start();
+  t3.Start();
+  t4.Start();
+
+  t1.Join();
+  t2.Join();
+  t3.Join();
+  t4.Join();
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTL_SUPPORT

test/unittests/run-all-unittests.cc

@@ -42,5 +42,6 @@ int main(int argc, char** argv) {
   testing::AddGlobalTestEnvironment(new DefaultPlatformEnvironment);
   v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
   v8::V8::InitializeExternalStartupData(argv[0]);
+  v8::V8::InitializeICUDefaultLocation(argv[0]);
   return RUN_ALL_TESTS();
 }