Expose Service Describer in Dart mojo package

mojo/dart/packages/mojo_services/lib/notifications/notifications.mojom.dart

Index: mojo/dart/packages/mojo_services/lib/notifications/notifications.mojom.dart
diff --git a/mojo/dart/packages/mojo_services/lib/notifications/notifications.mojom.dart b/mojo/dart/packages/mojo_services/lib/notifications/notifications.mojom.dart
index 409c510c803babf72d2d680a4209c8553b988d1c..581fcf5be2669dfa2c464037a8995e3583e72912 100644
--- a/mojo/dart/packages/mojo_services/lib/notifications/notifications.mojom.dart
+++ b/mojo/dart/packages/mojo_services/lib/notifications/notifications.mojom.dart
@@ -504,11 +504,14 @@ const int _NotificationClient_onDismissedName = 1;
 
 
 class _NotificationClientServiceDescription 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 NotificationClient {
@@ -692,8 +695,13 @@ class NotificationClientStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _NotificationClientServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _NotificationClientServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }
 
 const int _Notification_updateName = 0;
@@ -702,11 +710,14 @@ const int _Notification_cancelName = 1;
 
 
 class _NotificationServiceDescription 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 Notification {
@@ -891,8 +902,13 @@ class NotificationStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _NotificationServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _NotificationServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }
 
 const int _NotificationService_postName = 0;
@@ -900,11 +916,14 @@ const int _NotificationService_postName = 0;
 
 
 class _NotificationServiceServiceDescription 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 NotificationService {
@@ -1077,8 +1096,13 @@ class NotificationServiceStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _NotificationServiceServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _NotificationServiceServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }