Stop working around issue 7781 in Pub.

utils/pub/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.
 
 /// Helpers for dealing with HTTP.
 library pub.http;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:json' as json;
@@ skipping 40 matching lines @@
       // 401 responses should be handled by the OAuth2 client. It's very
       // unlikely that they'll be returned by non-OAuth2 requests.
       if (status < 400 || status == 401) {
         return new Future.immediate(streamedResponse);
       }
 
       return http.Response.fromStream(streamedResponse).then((response) {
         throw new PubHttpException(response);
       });
     }).catchError((asyncError) {
-      var e = getRealError(asyncError);
-      if (e is SocketIOException &&
-          e.osError != null &&
-          (e.osError.errorCode == 8 ||
-           e.osError.errorCode == -2 ||
-           e.osError.errorCode == -5 ||
-           e.osError.errorCode == 11004)) {
+      if (asyncError.error is SocketIOException &&
+          asyncError.error.osError != null &&
+          (asyncError.error.osError.errorCode == 8 ||
+           asyncError.error.osError.errorCode == -2 ||
+           asyncError.error.osError.errorCode == -5 ||
+           asyncError.error.osError.errorCode == 11004)) {
         throw 'Could not resolve URL "${request.url.origin}".';
       }
       throw asyncError;
     }), HTTP_TIMEOUT, 'fetching URL "${request.url}"');
   }
 }
 
 /// The HTTP client to use for all HTTP requests.
 final httpClient = new PubHttpClient();
 
@@ skipping 50 matching lines @@
 
 /// Exception thrown when an HTTP operation fails.
 class PubHttpException implements Exception {
   final http.Response response;
 
   const PubHttpException(this.response);
 
   String toString() => 'HTTP error ${response.statusCode}: '
       '${response.reasonPhrase}';
 }