Expose Service Describer in Dart mojo package

mojo/dart/packages/mojo_services/lib/mojo/gfx/composition/scenes.mojom.dart

Index: mojo/dart/packages/mojo_services/lib/mojo/gfx/composition/scenes.mojom.dart
diff --git a/mojo/dart/packages/mojo_services/lib/mojo/gfx/composition/scenes.mojom.dart b/mojo/dart/packages/mojo_services/lib/mojo/gfx/composition/scenes.mojom.dart
index 89a09378e96f2a6995c31fe4120a449ec81fe667..5c8ca32278b5b918e9094ca4aecee899aa74ea98 100644
--- a/mojo/dart/packages/mojo_services/lib/mojo/gfx/composition/scenes.mojom.dart
+++ b/mojo/dart/packages/mojo_services/lib/mojo/gfx/composition/scenes.mojom.dart
@@ -737,11 +737,14 @@ const int _Scene_getSchedulerName = 3;
 
 
 class _SceneServiceDescription 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 Scene {
@@ -957,8 +960,13 @@ class SceneStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _SceneServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _SceneServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }
 
 const int _SceneListener_onResourceUnavailableName = 0;
@@ -966,11 +974,14 @@ const int _SceneListener_onResourceUnavailableName = 0;
 
 
 class _SceneListenerServiceDescription 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 SceneListener {
@@ -1182,8 +1193,13 @@ class SceneListenerStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _SceneListenerServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _SceneListenerServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }