Implements secure sockets on Mac OS with SecureTransport API

tests/standalone/io/secure_bad_certificate_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.
 
 // This test verifies that the bad certificate callback works.
 
 import "dart:async";
 import "dart:io";
 
 import "package:expect/expect.dart";
@@ skipping 37 matching lines @@
   await runClient(server.port, defaultContext, 'exception', 'throw');
   server.close();
 }
 
 
 Future runClient(int port,
                  SecurityContext context,
                  callbackReturns,
                  result) async {
   badCertificateCallback(X509Certificate certificate) {
-    Expect.equals('/CN=rootauthority', certificate.subject);
-    Expect.equals('/CN=rootauthority', certificate.issuer);
+    Expect.isTrue(certificate.subject.contains('rootauthority'));
+    Expect.isTrue(certificate.issuer.contains('rootauthority'));
     // Throw exception if one is requested.
     if (callbackReturns == 'exception') throw new CustomException();
     return callbackReturns;
   }
 
   try {
     var socket = await SecureSocket.connect(
         HOST_NAME,
         port,
         context: context,
         onBadCertificate: badCertificateCallback);
     Expect.equals('pass', result);  // Is rethrown below
     await socket.close();
   } catch (error)  {
     if (error is ExpectException) rethrow;
     Expect.notEquals(result, 'pass');
     if (result == 'fail') {
       Expect.isTrue(error is HandshakeException || error is ArgumentError);
     } else if (result == 'throw') {
       Expect.isTrue(error is CustomException);
     } else {
       Expect.fail('Unknown expectation $result');
     }
   }
 }