Fix a race in initialization of timezone cache in platform-win32.

src/date.h

Index: src/date.h
diff --git a/src/date.h b/src/date.h
index fcd61db046715003564a6e0fa73e009001361ab9..e9c9d9cb06ae9f1442a0c33bcd25d67c2449190a 100644
--- a/src/date.h
+++ b/src/date.h
@@ -62,11 +62,14 @@ class DateCache {
   // It is an invariant of DateCache that cache stamp is non-negative.
   static const int kInvalidStamp = -1;
 
-  DateCache() : stamp_(0) {
+  DateCache() : stamp_(0), tz_cache_(OS::CreateTimezoneCache()) {
     ResetDateCache();
   }
 
-  virtual ~DateCache() {}
+  virtual ~DateCache() {
+    OS::DisposeTimezoneCache(tz_cache_);
+    tz_cache_ = NULL;
+  }
 
 
   // Clears cached timezone information and increments the cache stamp.
@@ -113,7 +116,7 @@ class DateCache {
     if (time_ms < 0 || time_ms > kMaxEpochTimeInMs) {
       time_ms = EquivalentTime(time_ms);
     }
-    return OS::LocalTimezone(static_cast<double>(time_ms));
+    return OS::LocalTimezone(static_cast<double>(time_ms), tz_cache_);
   }
 
   // ECMA 262 - 15.9.5.26
@@ -182,11 +185,11 @@ class DateCache {
   // These functions are virtual so that we can override them when testing.
   virtual int GetDaylightSavingsOffsetFromOS(int64_t time_sec) {
     double time_ms = static_cast<double>(time_sec * 1000);
-    return static_cast<int>(OS::DaylightSavingsOffset(time_ms));
+    return static_cast<int>(OS::DaylightSavingsOffset(time_ms, tz_cache_));
   }
 
   virtual int GetLocalOffsetFromOS() {
-    double offset = OS::LocalTimeOffset();
+    double offset = OS::LocalTimeOffset(tz_cache_);
     ASSERT(offset < kInvalidLocalOffsetInMs);
     return static_cast<int>(offset);
   }
@@ -253,6 +256,8 @@ class DateCache {
   int ymd_year_;
   int ymd_month_;
   int ymd_day_;
+
+  TimezoneCache* tz_cache_;
 };
 
 } }   // namespace v8::internal