Expose Service Describer in Dart mojo package

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

Index: mojo/dart/packages/mojo_services/lib/input/input.mojom.dart
diff --git a/mojo/dart/packages/mojo_services/lib/input/input.mojom.dart b/mojo/dart/packages/mojo_services/lib/input/input.mojom.dart
index 6f02d5862ac0c4b8eb67bd92a7a131cc6118c7c5..c3ddfdc44f85fb4215c966f9fcb0a5d934e0cbc2 100644
--- a/mojo/dart/packages/mojo_services/lib/input/input.mojom.dart
+++ b/mojo/dart/packages/mojo_services/lib/input/input.mojom.dart
@@ -211,11 +211,14 @@ const int _InputClient_onBackButtonName = 0;
 
 
 class _InputClientServiceDescription 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 InputClient {
@@ -426,8 +429,13 @@ class InputClientStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _InputClientServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _InputClientServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }
 
 const int _InputService_setClientName = 0;
@@ -435,11 +443,14 @@ const int _InputService_setClientName = 0;
 
 
 class _InputServiceServiceDescription 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 InputService {
@@ -610,8 +621,13 @@ class InputServiceStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _InputServiceServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _InputServiceServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }