Fix build broken at 506df426d5d6.

fpdfsdk/src/javascript/JS_Value.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 <time.h>
+#include <cmath>
+#include <limits>
+
 #include "../../include/javascript/JavaScript.h"
 #include "../../include/javascript/JS_Define.h"
 #include "../../include/javascript/JS_Object.h"
 #include "../../include/javascript/JS_Value.h"
 #include "../../include/javascript/Document.h"
 
 static const FX_DWORD g_nan[2] = {0, 0x7FF80000};
 static double GetNan() {
   return *(double*)g_nan;
 }
@@ skipping 836 matching lines @@
   return day * 86400000 + time;
 }
 
 bool JS_PortIsNan(double d) {
   return d != d;
 }
 
 double JS_LocalTime(double d) {
   return JS_GetDateTime() + _getDaylightSavingTA(d);
 }