Fixing documentation for HttpRequest

tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate

 // 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.
 
 part of $LIBRARYNAME;
 
 /**
  * A utility for retrieving data from a URL.
  *
  * HttpRequest can be used to obtain data from http, ftp, and file
  * protocols.
  *
  * For example, suppose we're developing these API docs, and we
  * wish to retrieve the HTML of the top-level page and print it out.
  * The easiest way to do that would be:
  *
- *     var httpRequest = HttpRequest.get('http://api.dartlang.org',
- *         (request) => print(request.responseText));
+ *     HttpRequest.getString('http://api.dartlang.org').then((response) {
+ *       print(response);
+ *     });
  *
  * **Important**: With the default behavior of this class, your
  * code making the request should be served from the same origin (domain name,
  * port, and application layer protocol) as the URL you are trying to access
  * with HttpRequest. However, there are ways to
  * [get around this restriction](http://www.dartlang.org/articles/json-web-service/#note-on-jsonp).
  *
  * See also:
  *
  * * [Dart article on using HttpRequests](http://www.dartlang.org/articles/json-web-service/#getting-data)
@@ skipping 112 matching lines @@
 $if DART2JS
     var xhr = new HttpRequest();
     return JS('bool', '"onloadend" in #', xhr);
 $else
     return true;
 $endif
   }
 
 $!MEMBERS
 }