Remove duplicate isLeapYear

Source/platform/DateComponents.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 35 matching lines @@
 
 // HTML5 specification defines maximum week of year is 53.
 const int DateComponents::maximumWeekNumber = 53;
 
 static const int maximumMonthInMaximumYear = 8; // This is September, since months are 0 based.
 static const int maximumDayInMaximumMonth = 13;
 static const int maximumWeekInMaximumYear = 37; // The week of 275760-09-13
 
 static const int daysInMonth[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
-static bool isLeapYear(int year)
-{
-    if (year % 4)
-        return false;
-    if (!(year % 400))
-        return true;
-    if (!(year % 100))
-        return false;
-    return true;
-}
-
 // 'month' is 0-based.
 static int maxDayOfMonth(int year, int month)
 {
     if (month != 1) // February?
         return daysInMonth[month];
     return isLeapYear(year) ? 29 : 28;
 }
 
 // 'month' is 0-based.
 static int dayOfWeek(int year, int month, int day)
@@ skipping 637 matching lines @@
     case Week:
         return String::format("%04d-W%02d", m_year, m_week);
     case Invalid:
         break;
     }
     ASSERT_NOT_REACHED();
     return String("(Invalid DateComponents)");
 }
 
 } // namespace WebCore