Fix html/js test on Dartium.

tests/html/js_test.dart

Index: tests/html/js_test.dart
diff --git a/tests/html/js_test.dart b/tests/html/js_test.dart
index 39cff4c5cfc43d2315d7d8340be657f2f200bfa8..ba5d00746d811f6884f9020d031cb891e3ef9f9a 100644
--- a/tests/html/js_test.dart
+++ b/tests/html/js_test.dart
@@ -295,9 +295,9 @@ main() {
         // Test that we are not pulling cached proxy from the prototype
         // when asking for a proxy for the object.
         final proto = context['someProto'];
-        expect(proto['role'], same('proto'));
+        expect(proto['role'], equals('proto'));
         final obj = context['someObject'];
-        expect(obj['role'], same('object'));
+        expect(obj['role'], equals('object'));
       });
     });