Detect and wrap JS-CustomEvents if applicable. Include created_watcher and

pkg/polymer/lib/src/events.dart

Index: pkg/polymer/lib/src/events.dart
diff --git a/pkg/polymer/lib/src/events.dart b/pkg/polymer/lib/src/events.dart
index 503445fbf827ac91cb9ba0ea4a97d555adb80c2c..1817658405ec4e86e2c17c09a8dee77abad1fa1e 100644
--- a/pkg/polymer/lib/src/events.dart
+++ b/pkg/polymer/lib/src/events.dart
@@ -57,7 +57,16 @@ abstract class PolymerEventBindings {
     }
 
     if (controller is Polymer) {
-      var args = [e, e.detail, e.currentTarget];
+      var detail = null;
+      if (e is CustomEvent) {

[Siggi Cherem (dart-lang), 2014/06/06 22:42:24]

this part was a regression, I think (we used to check for e is CustomEvent, but
I didn't realize this got deleted in the new roll).

[Jennifer Messerly, 2014/06/09 16:54:37]

ah, right... it should've been:

    var detail = e is CustomEvent ? e.detail : null;

Should I make a quick patch for it w/ regression test?

[Siggi Cherem (dart-lang), 2014/06/10 01:39:34]

I think that's OK. The current test I'm adding should cover this too.

+        detail = e.detail;
+        // Dart note: to improve interop with polymer.js elements, we try to
+        // proxy any js detail objects.
+        if (detail == null) {

[justinfagnani, 2014/06/06 23:37:05]

I'm confused by this, are the Dart detail and the JS detail using separate
storage?

[Jennifer Messerly, 2014/06/09 16:54:37]

for some reason, CustomEvent is a bit wacky in dart:html (see below). but yeah,
I would expect it to be non-null for JS objects...

@DomName('CustomEvent')
class CustomEvent extends Event {
  var _dartDetail;

  factory CustomEvent(String type,
      {bool canBubble: true, bool cancelable: true, Object detail}) {

    final CustomEvent e = document._createEvent('CustomEvent');

    e._dartDetail = detail;

    // Only try setting the detail if it's one of these types to avoid
    // first-chance exceptions. Can expand this list in the future as needed.
    if (detail is List || detail is Map || detail is String || detail is num) {
      try {
        e._initCustomEvent(type, canBubble, cancelable, detail);
      } catch(_) {
        e._initCustomEvent(type, canBubble, cancelable, null);
      }
    } else {
      e._initCustomEvent(type, canBubble, cancelable, null);
    }

    return e;
  }

  @DomName('CustomEvent.detail')
  get detail {
    if (_dartDetail != null) {
      return _dartDetail;
    }
    return _detail;
  }
  // To suppress missing implicit constructor warnings.
  factory CustomEvent._() { throw new UnsupportedError("Not supported"); }

  @DomName('CustomEvent.detail')
  @DocsEditable()
  Object get _detail => _blink.Native_CustomEvent_detail_Getter(this);

  @DomName('CustomEvent.initCustomEvent')
  @DocsEditable()
  void _initCustomEvent(String typeArg, bool canBubbleArg, bool cancelableArg,
Object detailArg) => _blink.Native_CustomEvent_initCustomEvent_Callback(this,
typeArg, canBubbleArg, cancelableArg, detailArg);

}

[Siggi Cherem (dart-lang), 2014/06/10 01:39:34]

Seems like the scenario I hit when wrapping a core element was including a DOM
node in the detail. 

+          detail = new JsObject.fromBrowserObject(e)['detail'];
+        }
+      }
+      var args = [e, detail, e.currentTarget];
       controller.dispatchMethod(controller, method, args);
     } else {
       throw new StateError('controller $controller is not a '