Support dart2js in pub serve.

sdk/lib/_internal/pub/test/transformer/dart2js/allows_import_in_dart_code_test.dart

Index: sdk/lib/_internal/pub/test/transformer/dart2js/allows_import_in_dart_code_test.dart
diff --git a/sdk/lib/_internal/pub/test/transformer/dart2js/allows_import_in_dart_code_test.dart b/sdk/lib/_internal/pub/test/transformer/dart2js/allows_import_in_dart_code_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..441ef8bc09cf68838459fb7fab8d72a9af54d1e5
--- /dev/null
+++ b/sdk/lib/_internal/pub/test/transformer/dart2js/allows_import_in_dart_code_test.dart
@@ -0,0 +1,53 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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;
+
+import 'package:scheduled_test/scheduled_test.dart';
+
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+import '../../serve/utils.dart';
+
+main() {
+  initConfig();
+  integration("handles imports in the Dart code", () {
+    d.dir("foo", [
+      d.libPubspec("foo", "0.0.1"),
+      d.dir("lib", [
+        d.file("foo.dart", """
+library foo;
+foo() => 'footext';
+""")
+      ])
+    ]).create();
+
+    d.dir(appPath, [
+      d.appPubspec({
+        "foo": {"path": "../foo"}
+      }),
+      d.dir("lib", [
+        d.file("lib.dart", """
+library lib;
+lib() => 'libtext';
+""")
+      ]),
+      d.dir("web", [
+        d.file("main.dart", """
+import 'package:foo/foo.dart';
+import 'package:myapp/lib.dart';
+void main() {
+  print(foo());
+  print(lib());
+}
+""")
+      ])
+    ]).create();
+
+    startPubServe(shouldInstallFirst: true);
+    requestShouldSucceed("main.dart.js", contains("footext"));
+    requestShouldSucceed("main.dart.js", contains("libtext"));
+    endPubServe();
+  });
+}