Remove duplicate isLeapYear

Source/platform/DateComponents.cpp

Index: Source/platform/DateComponents.cpp
diff --git a/Source/platform/DateComponents.cpp b/Source/platform/DateComponents.cpp
index e4cb1208f0d3c1c5ab754bee3fdfc0d06f452662..62f9033dae42a2c584bd5d4223be16ba187ad4d5 100644
--- a/Source/platform/DateComponents.cpp
+++ b/Source/platform/DateComponents.cpp
@@ -53,17 +53,6 @@ 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)
 {