Introduce isWindowsVistaOrGreater() as replacement of windowsVersion()

Source/platform/win/SystemInfo.h

 /*
  * Copyright (C) 2009 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 13 matching lines @@
  */
 
 #ifndef SystemInfo_h
 #define SystemInfo_h
 
 #include "platform/PlatformExport.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
-// NOTE: Keep these in order so callers can do things like
-// "if (windowsVersion() >= WindowsVista) ...". It's OK to change or add values,
-// though.
-enum WindowsVersion {
-    // CE-based versions
-    WindowsCE1 = 0,
-    WindowsCE2,
-    WindowsCE3,
-    WindowsCE4,
-    WindowsCE5,
-    WindowsCE6,
-    WindowsCE7,
-    // 3.x-based versions
-    Windows3_1,
-    // 9x-based versions
-    Windows95,
-    Windows98,
-    WindowsME,
-    // NT-based versions
-    WindowsNT3,
-    WindowsNT4,
-    Windows2000,
-    WindowsXP,
-    WindowsServer2003,
-    WindowsVista,
-    WindowsServer2008,
-    Windows7,
-};
-
-// If supplied, |major| and |minor| are set to the OSVERSIONINFO::dwMajorVersion
-// and dwMinorVersion field values, respectively.
-PLATFORM_EXPORT WindowsVersion windowsVersion(int* major = 0, int* minor = 0);
+PLATFORM_EXPORT bool isWindowsVistaOrGreater();
 
 } // namespace WebCore
 
 #endif // SystemInfo_h