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

src/platform-linux.cc

Index: src/platform-linux.cc
diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index b35cd2845499180134e79170b42f36e42ff21ff7..527b9f616dc127418b9117acc518f7c25561eca8 100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -118,7 +118,7 @@ bool OS::ArmUsingHardFloat() {
 #endif  // def __arm__
 
 
-const char* OS::LocalTimezone(double time) {
+const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
   struct tm* t = localtime(&tv);
@@ -127,7 +127,7 @@ const char* OS::LocalTimezone(double time) {
 }
 
 
-double OS::LocalTimeOffset() {
+double OS::LocalTimeOffset(TimezoneCache* cache) {
   time_t tv = time(NULL);
   struct tm* t = localtime(&tv);
   // tm_gmtoff includes any daylight savings offset, so subtract it.