Implement JsMethodMirror.parameters.

dart/tests/lib/mirrors/constructors_test.dart

Index: dart/tests/lib/mirrors/constructors_test.dart
diff --git a/dart/tests/lib/mirrors/constructors_test.dart b/dart/tests/lib/mirrors/constructors_test.dart
index 1a717a7a9f44d25513b45ee31d994187825e3e6d..89fc874786241e38946ea1d13ec519ae94374f7a 100644
--- a/dart/tests/lib/mirrors/constructors_test.dart
+++ b/dart/tests/lib/mirrors/constructors_test.dart
@@ -8,7 +8,7 @@ import 'dart:mirrors';
 
 import 'package:expect/expect.dart';
 
-import 'reflect_model_test.dart';
+import 'stringify.dart';
 
 class Foo {
 }
@@ -45,4 +45,11 @@ main() {
          ' Biz.named: Method(s(Biz.named) in s(Biz), constructor)}',
          bizConstructors);
   print(bizConstructors);
+
+  expect('[]', fooConstructors.values.single.parameters);
+  expect('[]', barConstructors.values.single.parameters);
+  expect('[]', bazConstructors.values.single.parameters);
+  for (var constructor in bizConstructors.values) {
+    expect('[]', constructor.parameters);
+  }
 }