Add support for https scheme in dart:io HttpClient.

sdk/lib/io/http.dart

 // Copyright (c) 2012, 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.
 
 /**
  * HTTP status codes.
  */
 abstract class HttpStatus {
   static const int CONTINUE = 100;
   static const int SWITCHING_PROTOCOLS = 101;
@@ skipping 716 matching lines @@
  * HTTP client factory. The [HttpClient] handles all the sockets associated
  * with the [HttpClientConnection]s and when the endpoint supports it, it will
  * try to reuse opened sockets for several requests to support HTTP 1.1
  * persistent connections. This means that sockets will be kept open for some
  * time after a requests have completed, unless HTTP procedures indicate that it
  * must be closed as part of completing the request. Use [:HttpClient.shutdown:]
  * to force close the idle sockets.
  */
 abstract class HttpClient {
   static const int DEFAULT_HTTP_PORT = 80;
+  static const int DEFAULT_HTTPS_PORT = 443;
 
   factory HttpClient() => new _HttpClient();
 
   /**
    * Opens a HTTP connection. The returned [HttpClientConnection] is
    * used to register callbacks for asynchronous events on the HTTP
    * connection. The "Host" header for the request will be set to the
    * value [host]:[port]. This can be overridden through the
    * HttpClientRequest interface before the request is sent. NOTE if
    * [host] is an IP address this will still be set in the "Host"
@@ skipping 345 matching lines @@
 class RedirectLimitExceededException extends RedirectException {
   const RedirectLimitExceededException(List<RedirectInfo> redirects)
       : super("Redirect limit exceeded", redirects);
 }
 
 
 class RedirectLoopException extends RedirectException {
   const RedirectLoopException(List<RedirectInfo> redirects)
       : super("Redirect loop detected", redirects);
 }