Remove AsyncError with Expando.

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 43 matching lines @@
       // to pass along 400 responses from the token endpoint.
       var tokenRequest = urisEqual(
           streamedResponse.request.url, oauth2.tokenEndpoint);
       if (status < 400 || status == 401 || (status == 400 && tokenRequest)) {
         return streamedResponse;
       }
 
       return http.Response.fromStream(streamedResponse).then((response) {
         throw new PubHttpException(response);
       });
-    }).catchError((asyncError) {
-      if (asyncError.error is SocketIOException &&
-          asyncError.error.osError != null) {
-        if (asyncError.error.osError.errorCode == 8 ||
-            asyncError.error.osError.errorCode == -2 ||
-            asyncError.error.osError.errorCode == -5 ||
-            asyncError.error.osError.errorCode == 11001 ||
-            asyncError.error.osError.errorCode == 11004) {
+    }).catchError((error) {
+      if (error is SocketIOException &&
+          error.osError != null) {
+        if (error.osError.errorCode == 8 ||
+            error.osError.errorCode == -2 ||
+            error.osError.errorCode == -5 ||
+            error.osError.errorCode == 11001 ||
+            error.osError.errorCode == 11004) {
           throw 'Could not resolve URL "${request.url.origin}".';
-        } else if (asyncError.error.osError.errorCode == -12276) {
+        } else if (error.osError.errorCode == -12276) {
           throw 'Unable to validate SSL certificate for '
               '"${request.url.origin}".';
         }
       }
-      throw asyncError;
+      throw error;
     }), HTTP_TIMEOUT, 'fetching URL "${request.url}"');
   }
 
   /// Logs the fact that [request] was sent, and information about it.
   void _logRequest(http.BaseRequest request) {
     var requestLog = new StringBuffer();
     requestLog.writeln("HTTP ${request.method} ${request.url}");
     request.headers.forEach((name, value) =>
         requestLog.writeln(_logField(name, value)));
 
@@ skipping 104 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}';
 }