Switch pkg packages, pub, and dartdoc to use package: imports.

utils/tests/pub/test_pub.dart

Index: utils/tests/pub/test_pub.dart
diff --git a/utils/tests/pub/test_pub.dart b/utils/tests/pub/test_pub.dart
index 2073f4227f4be49eb2e7fe0bc5086b9b98df8014..cfd1475bd1527d0986bbd5d19f545378383add60 100644
--- a/utils/tests/pub/test_pub.dart
+++ b/utils/tests/pub/test_pub.dart
@@ -16,15 +16,14 @@ import 'dart:math';
 import 'dart:uri';
 import 'dart:utf';
 
-import '../../../pkg/http/lib/testing.dart';
-import '../../../pkg/oauth2/lib/oauth2.dart' as oauth2;
-import '../../../pkg/pathos/lib/path.dart' as path;
-import '../../../pkg/scheduled_test/lib/scheduled_process.dart';
-import '../../../pkg/scheduled_test/lib/scheduled_server.dart';
-import '../../../pkg/scheduled_test/lib/scheduled_test.dart';
-import '../../../pkg/yaml/lib/yaml.dart';
-
-import '../../lib/file_system.dart' as fs;
+import 'package:http/testing.dart';
+import 'package:oauth2/oauth2.dart' as oauth2;
+import 'package:pathos/path.dart' as path;
+import 'package:scheduled_test/scheduled_process.dart';
+import 'package:scheduled_test/scheduled_server.dart';
+import 'package:scheduled_test/scheduled_test.dart';
+import 'package:yaml/yaml.dart';
+
 import '../../pub/entrypoint.dart';
 // TODO(rnystrom): Using "gitlib" as the prefix here is ugly, but "git" collides
 // with the git descriptor method. Maybe we should try to clean up the top level
@@ -341,9 +340,10 @@ ScheduledProcess startPub({List args, Future<Uri> tokenEndpoint}) {
   }
 
   // Find the main pub entrypoint.
-  var pubPath = fs.joinPaths(testDirectory, '../../pub/pub.dart');
+  var pubPath = path.join(testDirectory, '..', '..', 'pub', 'pub.dart');
 
-  var dartArgs = ['--checked', pubPath, '--trace'];
+  var dartArgs = ['--package-root=$packageRoot/', '--checked', pubPath,
+      '--trace'];
   dartArgs.addAll(args);
 
   if (tokenEndpoint == null) tokenEndpoint = new Future.immediate(null);