Add HttpServer.idleTimeout for closing idle keep-alive connections.

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 186 matching lines @@
 
   /**
    * Set and get the default value of the `Server` header for all responses
    * generated by this [HttpServer]. The default value is
    * `Dart/<version> (dart:io)`.
    *
    * If the serverHeader is set to `null`, no default `Server` header will be
    * added to each response.
    */
   String serverHeader;
+
+  /**
+   * Get or set the timeout used for idle keep-alive connections. If no further
+   * request is seen within [idleTimeout] after the previous request was
+   * completed, the connection is droped.
+   *
+   * Default is 120 seconds.
+   *
+   * To disable, set [idleTimeout] to `null`.
+   */
+  Duration idleTimeout;
 }
 
 
 /**
  * Summary statistics about an [HttpServer]s current socket connections.
  */
 class HttpConnectionsInfo {
   /**
    * Total number of socket connections.
    */
@@ skipping 1294 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;
 }