Fix indexeddb tests to implement proper setVersion semantics.

tests/html/indexeddb_4_test.dart

Index: tests/html/indexeddb_4_test.dart
diff --git a/tests/html/indexeddb_4_test.dart b/tests/html/indexeddb_4_test.dart
index bc43835a24ac64c2a004332bdf420754b67564d7..4c25d3b6050cc75c70b2b670ef198043d27bf6db 100644
--- a/tests/html/indexeddb_4_test.dart
+++ b/tests/html/indexeddb_4_test.dart
@@ -32,7 +32,10 @@ class Test {
           db.deleteObjectStore(STORE_NAME);
         } catch (IDBDatabaseException e) { }
         db.createObjectStore(STORE_NAME);
-        writeItems(0);
+
+        var transaction = e.target.result;
+        transaction.on.complete.add(expectAsync1((e) => writeItems(0)));
+        transaction.on.error.add(fail);
       })
     );
     request.on.error.add(fail('setVersion error'));