Install barback from a hosted source in all tests.

test/run/does_not_run_on_transformer_error_test.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.
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 
 const SCRIPT = """
 main() {
   print("should not get here!");
@@ skipping 13 matching lines @@
   void apply(Transform transform) {
     // Don't run on the transformer itself.
     if (transform.primaryInput.id.path.startsWith("lib")) return;
     transform.logger.error('\${transform.primaryInput.id}.');
   }
 }
 """;
 
 main() {
    integration('does not run if a transformer has an error', () {
+     serveBarback();
+
      d.dir(appPath, [
        d.pubspec({
          "name": "myapp",
-         "transformers": ["myapp/src/transformer"]
+         "transformers": ["myapp/src/transformer"],
+         "dependencies": {"barback": "any"}
        }),
        d.dir("lib", [
          d.dir("src", [
            d.file("transformer.dart", TRANSFORMER)
          ])
        ]),
        d.dir("bin", [
          d.file("script.dart", SCRIPT)
        ])
      ]).create();
 
-     createLockFile('myapp', pkg: ['barback']);
-
+     pubGet();
      var pub = pubRun(args: ["bin/script"]);
 
      pub.stderr.expect("[Error from Failing]:");
      pub.stderr.expect("myapp|bin/script.dart.");
 
      // Note: no output from the script.
      pub.shouldExit();
    });
 }