Remove duplicate isLeapYear

Source/wtf/DateMath.h

 /*
  * Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2010 Research In Motion Limited. All rights reserved.
  *
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
@@ skipping 70 matching lines @@
 const double hoursPerDay = 24.0;
 const double minutesPerHour = 60.0;
 const double secondsPerHour = 60.0 * 60.0;
 const double secondsPerMinute = 60.0;
 const double msPerSecond = 1000.0;
 const double msPerMinute = 60.0 * 1000.0;
 const double msPerHour = 60.0 * 60.0 * 1000.0;
 const double msPerDay = 24.0 * 60.0 * 60.0 * 1000.0;
 const double msPerMonth = 2592000000.0;
 
-bool isLeapYear(int year);
+WTF_EXPORT bool isLeapYear(int year);
 
 // Returns the number of days from 1970-01-01 to the specified date.
 WTF_EXPORT double dateToDaysFrom1970(int year, int month, int day);
 WTF_EXPORT int msToYear(double ms);
 WTF_EXPORT double msToDays(double ms);
 WTF_EXPORT int msToMinutes(double ms);
 WTF_EXPORT int msToHours(double ms);
 WTF_EXPORT int dayInYear(int year, int month, int day);
 WTF_EXPORT int dayInYear(double ms, int year);
 WTF_EXPORT int monthFromDayInYear(int dayInYear, bool leapYear);
@@ skipping 19 matching lines @@
 using WTF::msToDays;
 using WTF::msToMinutes;
 using WTF::msToHours;
 using WTF::secondsPerMinute;
 using WTF::parseDateFromNullTerminatedCharacters;
 using WTF::makeRFC2822DateString;
 using WTF::calculateUTCOffset;
 using WTF::calculateDSTOffset;
 
 #endif // DateMath_h