Use the dart:async Stream API thoroughly 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 59 matching lines @@
 
     log.message('Downloading $id...');
 
     // Download and extract the archive to a temp directory.
     var tempDir;
     return Future.wait([
       httpClient.send(new http.Request("GET", new Uri.fromString(fullUrl)))
           .then((response) => response.stream),
       systemCache.createTempDir()
     ]).then((args) {
-      var stream = streamToInputStream(args[0]);
+      var stream = args[0];
       tempDir = args[1];
       return timeout(extractTarGz(stream, tempDir), HTTP_TIMEOUT,
           'fetching URL "$fullUrl"');
     }).then((_) {
       // Now that the install has succeeded, move it to the real location in
       // the cache. This ensures that we don't leave half-busted ghost
       // directories in the user's pub cache if an install fails.
       return renameDir(tempDir, destPath);
     }).then((_) => true);
   }
@@ skipping 68 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);
   }
 }