Update pub to use new import syntax.

utils/tests/pub/install/git/check_out_transitive_test.dart

 // Copyright (c) 2012, 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('pub_tests');
+library pub_tests;
 
-#import('dart:io');
+import 'dart:io';
 
-#import('../../test_pub.dart');
-#import('../../../../../pkg/unittest/unittest.dart');
+import '../../test_pub.dart';
+import '../../../../../pkg/unittest/unittest.dart';
 
 main() {
   test('checks out packages transitively from Git', () {
     ensureGit();
 
     git('foo.git', [
       libDir('foo'),
       libPubspec('foo', '1.0.0', [{"git": "../bar.git"}])
     ]).scheduleCreate();
 
@@ skipping 23 matching lines @@
         file('foo.dart', 'main() => "foo";')
       ]),
       dir('bar', [
         file('bar.dart', 'main() => "bar";')
       ])
     ]).scheduleValidate();
 
     run();
   });
 }