Expose Service Describer in Dart mojo package

mojo/dart/packages/mojo/lib/mojo/application_connector.mojom.dart

Index: mojo/dart/packages/mojo/lib/mojo/application_connector.mojom.dart
diff --git a/mojo/dart/packages/mojo/lib/mojo/application_connector.mojom.dart b/mojo/dart/packages/mojo/lib/mojo/application_connector.mojom.dart
index 324353dd4f5e1e7799a1262ad2184e357d32f0e9..a81067192d5c1828c1ec921a93cd49559e04f4fb 100644
--- a/mojo/dart/packages/mojo/lib/mojo/application_connector.mojom.dart
+++ b/mojo/dart/packages/mojo/lib/mojo/application_connector.mojom.dart
@@ -192,11 +192,14 @@ const int _ApplicationConnector_duplicateName = 1;
 
 
 class _ApplicationConnectorServiceDescription implements service_describer.ServiceDescription {
-  dynamic getTopLevelInterface([Function responseFactory]) => null;
+  dynamic getTopLevelInterface([Function responseFactory]) =>
+      responseFactory(null);
 
-  dynamic getTypeDefinition(String typeKey, [Function responseFactory]) => null;
+  dynamic getTypeDefinition(String typeKey, [Function responseFactory]) =>
+      responseFactory(null);
 
-  dynamic getAllTypeDefinitions([Function responseFactory]) => null;
+  dynamic getAllTypeDefinitions([Function responseFactory]) =>
+      responseFactory(null);
 }
 
 abstract class ApplicationConnector {
@@ -384,7 +387,7 @@ class ApplicationConnectorStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
+  static service_describer.ServiceDescription get serviceDescription =>
     new _ApplicationConnectorServiceDescription();
 }