Cleaning up event constructors

tests/html/storage_test.dart

Index: tests/html/storage_test.dart
diff --git a/tests/html/storage_test.dart b/tests/html/storage_test.dart
index cb00f86a89395c20f89a48cdc399af2e46c9653e..f24e1b7757a17482d716e42624101f18b4bdb0d9 100644
--- a/tests/html/storage_test.dart
+++ b/tests/html/storage_test.dart
@@ -16,4 +16,11 @@ main() {
     final stored = window.localStorage[key];
     expect(stored, value);
   });
+
+  test('event', () {
+    var event = new StorageEvent('something', oldValue: 'old', newValue: 'new');
+    expect(event is StorageEvent, isTrue);
+    expect(event.oldValue, 'old');
+    expect(event.newValue, 'new');
+  });
 }