Update XMLHttpRequest documentation.

lib/html/doc/interface/HttpRequestException.dartdoc

 // 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.
 
 // WARNING:
 //   This file contains documentation that is merged into the real source.
 //   Do not make code changes here.
 
 /// @domName XMLHttpRequestException
-interface XMLHttpRequestException {
+interface HttpRequestException {
 
   static final int ABORT_ERR = 102;
 
   static final int NETWORK_ERR = 101;
 
   /** @domName XMLHttpRequestException.code */
   final int code;
 
   /** @domName XMLHttpRequestException.message */
   final String message;
 
   /** @domName XMLHttpRequestException.name */
   final String name;
 
   /** @domName XMLHttpRequestException.toString */
   String toString();
 }