Fix reference to timezone variable - removed in VS 2015

fpdfsdk/src/jsapi/fxjs_v8.cpp

Index: fpdfsdk/src/jsapi/fxjs_v8.cpp
diff --git a/fpdfsdk/src/jsapi/fxjs_v8.cpp b/fpdfsdk/src/jsapi/fxjs_v8.cpp
index edade5fb947220c6d228fa0db149fd1ed2ce7391..1fb2a0882fb0b514db06859f598c81704eb401ad 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8.cpp
@@ -758,6 +758,13 @@ double _getLocalTZA()
 	time_t t = 0;
 	time(&t);
 	localtime(&t);
+#if _MSC_VER >= 1900
+  // In gcc and in Visual Studio prior to VS 2015 'timezone' is a global
+  // variable declared in time.h. That variable was deprecated and in VS 2015
+  // is removed, with _get_timezone replacing it.
+  long timezone = 0;
+  _get_timezone(&timezone);
+#endif
 	return (double)(-(timezone * 1000));
 }