Update charted to 0.4.8 and roll

packages/code_transformers/test/benchmarks_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.
+@TestOn('vm')
 library code_transformers.test.benchmarks_test;
 
 import 'package:barback/barback.dart';
 import 'package:code_transformers/benchmarks.dart';
-import 'package:unittest/compact_vm_config.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 
 main() {
-  useCompactVMConfiguration();
-
   test('can benchmark transformers', () {
     var transformer = new TestTransformer();
-    var transformers = [[transformer]];
+    var transformers = [
+      [transformer]
+    ];
     var id = new AssetId('foo', 'lib/bar.dart');
     var files = {
-        id: 'library foo.bar;',
+      id: 'library foo.bar;',
     };
     var benchmark = new TransformerBenchmark(transformers, files);
     return benchmark.measure().then((result) {
       expect(result, greaterThan(0));
       expect(transformer.filesSeen[id], isNotNull);
       expect(transformer.filesSeen[id], greaterThanOrEqualTo(10));
     });
   });
 }
 
 class TestTransformer extends Transformer {
   /// Map of the asset ids that were seen to how many times they were seen.
   Map<AssetId, int> filesSeen = {};
 
   @override
   bool isPrimary(AssetId id) => true;
 
   @override
   void apply(Transform transform) {
     filesSeen.putIfAbsent(transform.primaryInput.id, () => 0);
     filesSeen[transform.primaryInput.id] += 1;
   }
 }