Remove support for interface in dart2js.

tests/language/constructor_name_test.dart

Index: tests/language/constructor_name_test.dart
diff --git a/samples/tests/samples/browser/spirodraw_test.dart b/tests/language/constructor_name_test.dart
similarity index 50%
copy from samples/tests/samples/browser/spirodraw_test.dart
copy to tests/language/constructor_name_test.dart
index 2e6e5586cea32655f696a34410febbc6c139b9f9..93742a6e6363f0bac2187758f9345ec385439b67 100644
--- a/samples/tests/samples/browser/spirodraw_test.dart
+++ b/tests/language/constructor_name_test.dart
@@ -2,16 +2,15 @@
 // 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 spirodraw_test;
-
-import '../../../spirodraw/web/spirodraw.dart' as spirodraw;
+class Foo {
+  Bar.Foo(); /// 01: compile-time error
+  factory Bar(); /// 02: compile-time error
+  factory Bar.Baz(); /// 03: compile-time error
+}
 
-// @static-clean
 
-/**
- * This test exists to ensure that the spirodraw sample compiles without errors.
- */
 void main() {
-  
-}
-
+  new Foo();
+  new Foo.Foo(); /// 01: continued
+  new Foo.Baz(); /// 03: continued
+}