Converting tests over to using event streams.

tests/html/event_customevent_test.dart

Index: tests/html/event_customevent_test.dart
diff --git a/tests/html/event_customevent_test.dart b/tests/html/event_customevent_test.dart
index 2f506278320d24164e962aee02077f7e18bd0708..4e0ed4860202ae5b1a6673146a71b3dec6ebbf4c 100644
--- a/tests/html/event_customevent_test.dart
+++ b/tests/html/event_customevent_test.dart
@@ -26,9 +26,19 @@ eventTest(String name, Event eventFn(), void validate(Event),
 main() {
   useHtmlConfiguration();
 
-  eventTest('CustomEvent.initCustomEvent', () {
-    return new CustomEvent('foo', canBubble: false, cancelable: false,
+  test('custom events', () {
+    var provider = new EventStreamProvider<CustomEvent>('foo');
+    var el = new DivElement();
+
+    var fired = false;
+    provider.forTarget(el).listen((ev) {
+      fired = true;
+      expect(ev.detail, 'detail');
+    });
+
+    var ev = new CustomEvent('foo', canBubble: false, cancelable: false,
         detail: 'detail');
-  },
-  (ev) { expect(ev.detail, equals('detail')); });
+    el.dispatchEvent(ev);
+    expect(fired, isTrue);
+  });
 }