Add case to avoid warning when dart2js analyzes dart:io files

sdk/lib/io/secure_socket.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.
 
 part of dart.io;
 
 /**
  * A high-level class for communicating securely over a TCP socket, using
  * TLS and SSL. The [SecureSocket] exposes both a [Stream] and an
  * [IOSink] interface, making it ideal for using together with
@@ skipping 542 matching lines @@
                                            onError: _reportError,
                                            onDone: _doneHandler);
     } else {
       if (_socketSubscription.isPaused) {
         _socket.close();
         throw new ArgumentError(
             "Subscription passed to TLS upgrade is paused");
       }
       // If we are upgrading a socket that is already closed for read,
       // report an error as if we received READ_CLOSED during the handshake.
-      if (_socket._socket.closedReadEventSent) {
+      dynamic s = _socket;  // Cast to dynamic to avoid warning.

[karlklose, 2015/03/10 09:20:40]

'var s' would be shorter. Is there a better type you could use for _socket?

[Søren Gjesse, 2015/03/10 16:29:01]

The type is _RawSocket, but that is currently defined in the patch file.

+      if (s._socket.closedReadEventSent) {
         _eventDispatcher(RawSocketEvent.READ_CLOSED);
       }
       _socketSubscription
           ..onData(_eventDispatcher)
           ..onError(_reportError)
           ..onDone(_doneHandler);
     }
     try {
       _secureFilter.connect(address.host,
                             (address as dynamic)._in_addr,
@@ skipping 854 matching lines @@
 /**
  * An exception that happens in the handshake phase of establishing
  * a secure network connection, when looking up or verifying a
  * certificate.
  */
 class CertificateException extends TlsException {
   const CertificateException([String message = "",
                             OSError osError = null])
      : super._("CertificateException", message, osError);
 }