Get rid of unneeded Future.immediate() calls.

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 38 matching lines @@
 /// An in-memory cache of the user's OAuth2 credentials. This should always be
 /// the same as the credentials file stored in the system cache.
 Credentials _credentials;
 
 /// Delete the cached credentials, if they exist.
 Future clearCredentials(SystemCache cache) {
   _credentials = null;
   var credentialsFile = _credentialsFile(cache);
   return fileExists(credentialsFile).then((exists) {
     if (exists) return deleteFile(credentialsFile);
-    return new Future.immediate(null);
   });
 }
 
 /// Asynchronously passes an OAuth2 [Client] to [fn], and closes the client when
 /// the [Future] returned by [fn] completes.
 ///
 /// This takes care of loading and saving the client's credentials, as well as
 /// 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)) {
@@ skipping 20 matching lines @@
       throw asyncError;
     }
   });
 }
 
 /// 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 _loadCredentials(cache).then((credentials) {
     if (credentials == null) return _authorize();
-    return new Future.immediate(new Client(
-        _identifier, _secret, credentials, httpClient: curlClient));
+    return new Client(_identifier, _secret, credentials,
+        httpClient: curlClient);
   }).then((client) {
     return _saveCredentials(cache, client.credentials).then((_) => 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] will complete to null.
 Future<Credentials> _loadCredentials(SystemCache cache) {
   log.fine('Loading OAuth2 credentials.');
 
   if (_credentials != null) {
     log.fine('Using already-loaded credentials.');
     return new Future.immediate(_credentials);
   }
 
   var path = _credentialsFile(cache);
   return fileExists(path).then((credentialsExist) {
     if (!credentialsExist) {
       log.fine('No credentials found at $path.');
-      return new Future.immediate(null);
+      return;
     }
 
     return readTextFile(_credentialsFile(cache)).then((credentialsJson) {
       var credentials = new Credentials.fromJson(credentialsJson);
       if (credentials.isExpired && !credentials.canRefresh) {
         log.error("Pub's authorization to upload packages has expired and "
             "can't be automatically refreshed.");
         return null; // null means re-authorize
       }
 
@@ skipping 67 matching lines @@
       'Pub needs your authorization to upload packages on your behalf.\n'
       '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;
   });
 }