Remove AsyncError with Expando.

utils/pub/oauth2.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.
 
 library oauth2;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:uri';
 
@@ skipping 64 matching lines @@
 /// prompting the user for their authorization. It will also re-authorize and
 /// re-run [fn] if a recoverable authorization error is detected.
 Future withClient(SystemCache cache, Future fn(Client client)) {
   return _getClient(cache).then((client) {
     var completer = new Completer();
     return fn(client).whenComplete(() {
       client.close();
       // Be sure to save the credentials even when an error happens.
       _saveCredentials(cache, client.credentials);
     });
-  }).catchError((asyncError) {
-    if (asyncError.error is ExpirationException) {
+  }).catchError((error) {
+    if (error is ExpirationException) {
       log.error("Pub's authorization to upload packages has expired and "
           "can't be automatically refreshed.");
       return withClient(cache, fn);
-    } else if (asyncError.error is AuthorizationException) {
+    } else if (error is AuthorizationException) {
       var message = "OAuth2 authorization failed";
-      if (asyncError.error.description != null) {
-        message = "$message (${asyncError.error.description})";
+      if (error.description != null) {
+        message = "$message (${error.description})";
       }
       log.error("$message.");
       clearCredentials(cache);
       return withClient(cache, fn);
     } else {
-      throw asyncError;
+      throw error;
     }
   });
 }
 
 /// Gets a new OAuth2 client. If saved credentials are available, those are
 /// used; otherwise, the user is prompted to authorize the pub client.
 Future<Client> _getClient(SystemCache cache) {
   return new Future.of(() {
     var credentials = _loadCredentials(cache);
     if (credentials == null) return _authorize();
@@ skipping 87 matching lines @@
         response.statusCode = 404;
         response.close();
       }
     });
   })
   .then((client) {
     log.message('Successfully authorized.\n');
     return client;
   });
 }