Remove barback from the repo.

pkg/barback/test/transformer/lazy_check_content_and_rename.dart

Index: pkg/barback/test/transformer/lazy_check_content_and_rename.dart
diff --git a/pkg/barback/test/transformer/lazy_check_content_and_rename.dart b/pkg/barback/test/transformer/lazy_check_content_and_rename.dart
deleted file mode 100644
index 330ad22dcea37f8a16b6ddd795fe206215e82616..0000000000000000000000000000000000000000
--- a/pkg/barback/test/transformer/lazy_check_content_and_rename.dart
+++ /dev/null
@@ -1,20 +0,0 @@
-// 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 barback.test.transformer.lazy_check_content_and_rename;
-
-import 'dart:async';
-
-import 'package:barback/barback.dart';
-
-import 'declaring_check_content_and_rename.dart';
-
-class LazyCheckContentAndRenameTransformer
-    extends DeclaringCheckContentAndRenameTransformer
-    implements LazyTransformer {
-  LazyCheckContentAndRenameTransformer({String oldExtension,
-        String oldContent, String newExtension, String newContent})
-      : super(oldExtension: oldExtension, oldContent: oldContent,
-              newExtension: newExtension, newContent: newContent);
-}