Remove barback from the repo.

sdk/lib/_internal/pub/test/serve_packages.dart

 // Copyright (c) 2014, 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 serve_packages;
 
 import 'dart:async';
 import 'dart:convert';
 
 import 'package:path/path.dart' as p;
@@ skipping 135 matching lines @@
     }));
   }
 
   /// Serves the versions of [package] and all its dependencies that are
   /// currently checked into the Dart repository.
   void serveRepoPackage(String package) {
     _addPackage(name) {
       if (_packages.containsKey(name)) return;
       _packages[name] = [];
 
+      var root = packagePath(name);
       var pubspec = new Map.from(loadYaml(
-          readTextFile(p.join(repoRoot, 'pkg', name, 'pubspec.yaml'))));
+          readTextFile(p.join(root, 'pubspec.yaml'))));
 
       // Remove any SDK constraints since we don't have a valid SDK version
       // while testing.
       pubspec.remove('environment');
 
       _packages[name].add(new _ServedPackage(pubspec, [
         d.file('pubspec.yaml', yaml(pubspec)),
-        new d.DirectoryDescriptor.fromFilesystem('lib',
-            p.join(repoRoot, 'pkg', name, 'lib'))
+        new d.DirectoryDescriptor.fromFilesystem('lib', p.join(root, 'lib'))
       ]));
 
       if (pubspec.containsKey('dependencies')) {
         pubspec['dependencies'].keys.forEach(_addPackage);
       }
     }
 
     _addPackage(package);
   }
 
   /// Returns a Future that completes once all the [serve] calls have been fully
   /// processed.
   Future _await() {
     if (_futures.futures.isEmpty) return new Future.value();
     return _futures.future.then((_) {
       _futures = new FutureGroup();
     });
   }
 }
 
 /// A package that's intended to be served.
 class _ServedPackage {
   final Map pubspec;
   final List<d.Descriptor> contents;
 
   Version get version => new Version.parse(pubspec['version']);
 
   _ServedPackage(this.pubspec, this.contents);
 }