Fix reference to timezone variable - removed in VS 2015

fpdfsdk/src/jsapi/fxjs_v8.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../../core/include/fxcrt/fx_basic.h"
 #include "../../../core/include/fxcrt/fx_ext.h" 
 #include "../../include/jsapi/fxjs_v8.h"
 #include "../../include/fsdk_define.h"
@@ skipping 740 matching lines @@
 
 //JavaScript time implement begin.
 
 double _getLocalTZA()
 {
         if(!FSDK_IsSandBoxPolicyEnabled(FPDF_POLICY_MACHINETIME_ACCESS))
                 return 0;
         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));
 }
 
 int _getDaylightSavingTA(double d)
 {
         if(!FSDK_IsSandBoxPolicyEnabled(FPDF_POLICY_MACHINETIME_ACCESS))
                 return 0;
         time_t t = (time_t)(d/1000);
         struct tm * tmp = localtime(&t);
         if (tmp == NULL)
@@ skipping 263 matching lines @@
 {
         return d != d;
 }
 
 double JS_LocalTime(double d)
 {
         return JS_GetDateTime() + _getDaylightSavingTA(d);
 }
 
 //JavaScript time implement End.