Fix spelling mistake in r14188

runtime/bin/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 736 matching lines @@
    * Opens a HTTP connection using the POST method. See [openUrl] for details.
    */
   HttpClientConnection postUrl(Uri url);
 
   /**
    * Sets the function to be called when a site is requesting
    * authentication. The URL requested and the security realm from the
    * server are passed in the arguments [url] and [realm].
    *
    * The function returns a [Future] which should complete when the
-   * authentication have been resolved. If credentials cannot be
+   * authentication has been resolved. If credentials cannot be
    * provided the [Future] should complete with [false]. If
    * credentials are available the function should add these using
    * [addCredentials] before completing the [Future] with the value
    * [true].
    *
    * If the [Future] completes with true the request will be retried
    * using the updated credentials. Otherwise response processing will
    * continue normally.
    */
   set authenticate(Future<bool> f(Uri url, String scheme, String realm));
@@ skipping 282 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);
 }