Install barback from a hosted source in all tests.

test/transformer/prefers_transformer_to_library_name_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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_tests;
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import '../serve/utils.dart';
 
@@ skipping 10 matching lines @@
   Future apply(Transform transform) {
     return transform.primaryInput.readAsString().then((contents) {
       var id = transform.primaryInput.id.changeExtension(".wrong");
       transform.addOutput(new Asset.fromString(id, "\$contents.wrong"));
     });
   }
 }
 """;
 
 main() {
-  integration("prefers transformer.dart to <package name>.dart", () {
-    d.dir(appPath, [
-      d.pubspec({
-        "name": "myapp",
-        "transformers": ["myapp"]
-      }),
-      d.dir("lib", [
-        d.file("transformer.dart", REWRITE_TRANSFORMER),
-        d.file("myapp.dart", WRONG_TRANSFORMER)
-      ]),
-      d.dir("web", [
-        d.file("foo.txt", "foo")
-      ])
-    ]).create();
+   integration("prefers transformer.dart to <package name>.dart", () {
+     serveBarback();
 
-    createLockFile('myapp', pkg: ['barback']);
+     d.dir(appPath, [
+       d.pubspec({
+         "name": "myapp",
+         "transformers": ["myapp"],
+         "dependencies": {"barback": "any"}
+       }),
+       d.dir("lib", [
+         d.file("transformer.dart", REWRITE_TRANSFORMER),
+         d.file("myapp.dart", WRONG_TRANSFORMER)
+       ]),
+       d.dir("web", [
+         d.file("foo.txt", "foo")
+       ])
+     ]).create();
 
-    pubServe();
-    requestShouldSucceed("foo.out", "foo.out");
-    requestShould404("foo.wrong");
-    endPubServe();
-  });
+     pubGet();
+     pubServe();
+     requestShouldSucceed("foo.out", "foo.out");
+     requestShould404("foo.wrong");
+     endPubServe();
+   });
 }