Don't close existing connection on HttpServer close (and stream cancel).

sdk/lib/io/http.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;
 
 /**
  * HTTP status codes.
  */
 abstract class HttpStatus {
@@ skipping 153 matching lines @@
   /**
    * Attaches the HTTP server to an existing [ServerSocket]. When the
    * [HttpServer] is closed, the [HttpServer] will just detach itself,
    * closing current connections but not closing [serverSocket].
    */
   factory HttpServer.listenOn(ServerSocket serverSocket)
       => new _HttpServer.listenOn(serverSocket);
 
   /**
    * Permanently stops this [HttpServer] from listening for new
-   * connections.  This closes this [Stream] of [HttpRequest]s with a
+   * connections.  This closes the [Stream] of [HttpRequest]s with a
    * done event. The returned future completes when the server is
    * stopped. For a server started using [bind] or [bindSecure] this
    * means that the port listened on no longer in use.
+   *
+   * If [force] is `true`, active connections will be closed immediately.
    */
-  Future close();
+  Future close({bool force: false});
 
   /**
    * Returns the port that the server is listening on. This can be
    * used to get the actual port used when a value of 0 for [:port:] is
    * specified in the [bind] or [bindSecure] call.
    */
   int get port;
 
   /**
    * Returns the address that the server is listening on. This can be
@@ skipping 1407 matching lines @@
   final String message;
   final List<RedirectInfo> redirects;
 
   const RedirectException(String this.message,
                           List<RedirectInfo> this.redirects);
 
   String toString() => "RedirectException: $message";
 
   Uri get uri => redirects.last.location;
 }