Support named ctors.

client/dom/src/native_FactoryProvidersImplementation.dart

Index: client/dom/src/native_FactoryProvidersImplementation.dart
diff --git a/client/dom/src/native_FactoryProvidersImplementation.dart b/client/dom/src/native_FactoryProvidersImplementation.dart
index b1df0d30b82eae6cb49bec052febcd229be7f098..ee6c0d206b136baf0ab48c444ca2bd0866ad5bb6 100644
--- a/client/dom/src/native_FactoryProvidersImplementation.dart
+++ b/client/dom/src/native_FactoryProvidersImplementation.dart
@@ -11,11 +11,9 @@ class FactoryProviderImplementation {
 
   static EventSource createEventSource(String scriptUrl) native "EventSource_constructor_Callback";
 
-  // TODO(antonm): support named constructors generation.
-  static HTMLAudioElement createHTMLAudioElement([String src]) { throw 'Unimplemented.'; }
+  static HTMLAudioElement createHTMLAudioElement([String src]) native "HTMLAudioElement_constructor_Callback";
 
-  // TODO(antonm): support named constructors generation.
-  static HTMLOptionElement createHTMLOptionElement([String data, String value, bool defaultSelected, bool selected]) { throw 'Unimplemented.'; }
+  static HTMLOptionElement createHTMLOptionElement([String data, String value, bool defaultSelected, bool selected]) native "HTMLOptionElement_constructor_Callback";
 
   static  MediaController createMediaController() native "MediaController_constructor_Callback";