Upgrade to oauth2 1.0.0.

lib/src/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 pub.oauth2;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:oauth2/oauth2.dart';
@@ skipping 93 matching lines @@
     } else {
       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.sync(() {
-    var credentials = _loadCredentials(cache);
-    if (credentials == null) return _authorize();
+Future<Client> _getClient(SystemCache cache) async {
+  var credentials = _loadCredentials(cache);
+  if (credentials == null) return await _authorize();
 
-    var client = new Client(_identifier, _secret, credentials,
-        httpClient: httpClient);
-    _saveCredentials(cache, client.credentials);
-    return client;
-  });
+  var client = new Client(credentials,
+      identifier: _identifier,
+      secret: _secret,
+      // Google's OAuth2 API doesn't support basic auth.
+      basicAuth: false,
+      httpClient: httpClient);
+  _saveCredentials(cache, client.credentials);
+  return client;
 }
 
 /// Loads the user's OAuth2 credentials from the in-memory cache or the
 /// filesystem if possible.
 ///
 /// If the credentials can't be loaded for any reason, the returned [Future]
 /// completes to `null`.
 Credentials _loadCredentials(SystemCache cache) {
   log.fine('Loading OAuth2 credentials.');
 
@@ skipping 31 matching lines @@
 /// The path to the file in which the user's OAuth2 credentials are stored.
 String _credentialsFile(SystemCache cache) =>
     path.join(cache.rootDir, 'credentials.json');
 
 /// Gets the user to authorize pub as a client of pub.dartlang.org via oauth2.
 ///
 /// Returns a Future that completes to a fully-authorized [Client].
 Future<Client> _authorize() {
   var grant = new AuthorizationCodeGrant(
       _identifier,
-      _secret,
       authorizationEndpoint,
       tokenEndpoint,
+      secret: _secret,
+      // Google's OAuth2 API doesn't support basic auth.
+      basicAuth: false,
       httpClient: httpClient);
 
   // Spin up a one-shot HTTP server to receive the authorization code from the
   // Google OAuth2 server via redirect. This server will close itself as soon as
   // the code is received.
   var completer = new Completer();
   bindServer('localhost', 0).then((server) {
     shelf_io.serveRequests(server, (request) {
       if (request.url.path.isNotEmpty) {
         return new shelf.Response.notFound('Invalid URI.');
@@ skipping 20 matching lines @@
         'In a web browser, go to $authUrl\n'
         'Then click "Allow access".\n\n'
         'Waiting for your authorization...');
   });
 
   return completer.future.then((client) {
     log.message('Successfully authorized.\n');
     return client;
   });
 }