Some more removals of dart:utf.

pkg/csslib/test/nested_test.dart

 // Copyright (c) 2013, 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 nested_test;
 
-import 'dart:utf';
 import 'package:unittest/unittest.dart';
 import 'package:csslib/parser.dart';
 import 'package:csslib/visitor.dart';
 import 'testing.dart';
 
 List optionsCss = ['--no-colors', 'memory'];
 
 compileAndValidate(String input, String generated) {
   var errors = [];
   var stylesheet = compileCss(input, errors: errors, opts: optionsCss);
@@ skipping 587 matching lines @@
 
 main() {
   test('Selector and Nested Variations', selectorVariations);
   test('Simple nesting', simpleNest);
   test('Complex nesting', complexNest);
   test('@media nesting', mediaNesting);
   test('Simple &', simpleThis);
   test("Variations &", variationsThis);
   test('Complex &', complexThis);
 }