Make listDir and createSymlink synchronous in pub.

utils/pub/hosted_source.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 hosted_source;
 
 import 'dart:async';
 import 'dart:io' as io;
 import 'dart:json' as json;
 import 'dart:uri';
@@ skipping 100 matching lines @@
   ///
   /// There are two valid formats. A plain string refers to a package with the
   /// given name from the default host, while a map with keys "name" and "url"
   /// refers to a package with the given name from the host at the given URL.
   dynamic parseDescription(String containingPath, description,
                            {bool fromLockFile: false}) {
     _parseDescription(description);
     return description;
   }
 
-  Future<List<Package>> getCachedPackages() {
-    return defer(() {
-      var cacheDir = path.join(systemCacheRoot, 
-                               _getSourceDirectory(_defaultUrl)); 
-      if (!dirExists(cacheDir)) return [];
-    
-      return listDir(path.join(cacheDir)).then((entries) {
-        return entries.map((entry) => 
-          new Package.load(null, entry, systemCache.sources));
-      });  
-    });
+  List<Package> getCachedPackages() {
+    var cacheDir = path.join(systemCacheRoot,
+                             _getSourceDirectory(_defaultUrl));
+    if (!dirExists(cacheDir)) return [];
+  
+    return listDir(path.join(cacheDir)).map((entry) =>
+        new Package.load(null, entry, systemCache.sources));
   }
   
   /// When an error occurs trying to read something about [package] from [url],
   /// this tries to translate into a more user friendly error message. Always
   /// throws an error, either the original one or a better one.
   void _throwFriendlyError(AsyncError asyncError, package, url) {
     if (asyncError.error is PubHttpException &&
         asyncError.error.response.statusCode == 404) {
       throw 'Could not find package "$package" at $url.';
     }
@@ skipping 62 matching lines @@
   }
 
   var name = description["name"];
   if (name is! String) {
     throw new FormatException("The 'name' key must have a string value.");
   }
 
   var url = description.containsKey("url") ? description["url"] : _defaultUrl;
   return new Pair<String, String>(name, url);
 }