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

src/platform.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 141 matching lines @@
       :"r"(kMacTlsBaseOffset), "r"(index));
 #endif
   return result;
 }
 
 #endif
 
 #endif  // V8_NO_FAST_TLS
 
 
+class TimezoneCache;
+
+
 // ----------------------------------------------------------------------------
 // OS
 //
 // This class has static methods for the different platform specific
 // functions. Add methods here to cope with differences between the
 // supported platforms.
 
 class OS {
  public:
   // Initializes the platform OS support that depend on CPU features. This is
   // called after CPU initialization.
   static void PostSetUp();
 
   // Returns the accumulated user time for thread. This routine
   // can be used for profiling. The implementation should
   // strive for high-precision timer resolution, preferable
   // micro-second resolution.
   static int GetUserTime(uint32_t* secs,  uint32_t* usecs);
 
   // Returns current time as the number of milliseconds since
   // 00:00:00 UTC, January 1, 1970.
   static double TimeCurrentMillis();
 
+  static TimezoneCache* CreateTimezoneCache();
+  static void DisposeTimezoneCache(TimezoneCache* cache);
+  static void ClearTimezoneCache(TimezoneCache* cache);
+
   // Returns a string identifying the current time zone. The
   // timestamp is used for determining if DST is in effect.
-  static const char* LocalTimezone(double time);
+  static const char* LocalTimezone(double time, TimezoneCache* cache);
 
   // Returns the local time offset in milliseconds east of UTC without
   // taking daylight savings time into account.
-  static double LocalTimeOffset();
+  static double LocalTimeOffset(TimezoneCache* cache);
 
   // Returns the daylight savings offset for the given time.
-  static double DaylightSavingsOffset(double time);
-
-  static void TimeZoneChanged();
+  static double DaylightSavingsOffset(double time, TimezoneCache* cache);
 
   // Returns last OS error.
   static int GetLastError();
 
   static FILE* FOpen(const char* path, const char* mode);
   static bool Remove(const char* path);
 
   // Opens a temporary file, the file is auto removed on close.
   static FILE* OpenTemporaryFile();
 
@@ skipping 405 matching lines @@
   char name_[kMaxThreadNameLength];
   int stack_size_;
   Semaphore* start_semaphore_;
 
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_H_