pkg/csslib: use pkg/test and allow latest version of logging pkg

test/var_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 var_test;
 
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
+
 import 'testing.dart';
 
 compileAndValidate(String input, String generated) {
   var errors = [];
   var stylesheet = compileCss(input, errors: errors, opts: options);
   expect(stylesheet != null, true);
   expect(errors.isEmpty, true, reason: errors.toString());
   expect(prettyPrint(stylesheet), generated);
 }
 
@@ skipping 898 matching lines @@
   test('Expressions var', expressionsVar);
   test('Default value in var()', defaultVar);
   test('CSS Parser only var', parserVar);
   test('Var syntax', testVar);
   test('Indirects', testIndirects);
   test('Forward Refs', undefinedVars);
   test('Less syntax', testLess);
   test('Polyfill', polyfill);
   test('Multi-file', includes);
 }