Add test directive to include other files used by a test in its compiled output directory.

tests/standalone/io/raw_secure_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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
+// OtherResources=certificates/server_chain.pem
+// OtherResources=certificates/server_key.pem
+// OtherResources=certificates/trusted_certs.pem
 
 import "package:expect/expect.dart";
 import "package:path/path.dart";
 import "dart:async";
 import "dart:io";
 import "dart:isolate";
 
 String localFile(path) => Platform.script.resolve(path).toFilePath();
 
 SecurityContext serverContext = new SecurityContext()
@@ skipping 45 matching lines @@
         server.close();
         break;
       default: throw "Unexpected event $event";
     }
   }, onError: (e, trace) {
     String msg = "onError handler of RawSecureSocket stream hit $e";
     if (trace != null) msg += "\nStackTrace: $trace";
     Expect.fail(msg);
   });
 }