Don't run larger datagram tests on Mac OS

tests/standalone/io/raw_datagram_socket_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import "dart:async";
 import "dart:io";
 import "dart:typed_data";
 
 import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
@@ skipping 304 matching lines @@
 main() {
   testDatagramBroadcastOptions();
   testDatagramMulticastOptions();
   if (!Platform.isMacOS) {
     testDatagramSocketReuseAddress();
   }
   testBroadcast();
   testLoopbackMulticast();
   testSendReceive(InternetAddress.LOOPBACK_IP_V4, 1000);
   testSendReceive(InternetAddress.LOOPBACK_IP_V6, 1000);
-  testSendReceive(InternetAddress.LOOPBACK_IP_V4, 32 * 1024);
-  testSendReceive(InternetAddress.LOOPBACK_IP_V6, 32 * 1024);
-  testSendReceive(InternetAddress.LOOPBACK_IP_V4, 64 * 1024 - 32);
-  testSendReceive(InternetAddress.LOOPBACK_IP_V6, 64 * 1024 - 32);
+  if (!Platform.isMacOS) {

[kustermann, 2015/10/06 08:21:29]

Maybe add a comment about why they fail (I assume default MTU is lower)?

+    testSendReceive(InternetAddress.LOOPBACK_IP_V4, 32 * 1024);
+    testSendReceive(InternetAddress.LOOPBACK_IP_V6, 32 * 1024);
+    testSendReceive(InternetAddress.LOOPBACK_IP_V4, 64 * 1024 - 32);
+    testSendReceive(InternetAddress.LOOPBACK_IP_V6, 64 * 1024 - 32);
+  }
 }