Expose Service Describer in Dart mojo package

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

Index: mojo/dart/packages/mojo_services/lib/nfc/nfc.mojom.dart
diff --git a/mojo/dart/packages/mojo_services/lib/nfc/nfc.mojom.dart b/mojo/dart/packages/mojo_services/lib/nfc/nfc.mojom.dart
index 85058cb9a106c17f66b2e448300fb0abbfb5fd64..92faec658a403ccc8160ec36bca7a7d457c59c9e 100644
--- a/mojo/dart/packages/mojo_services/lib/nfc/nfc.mojom.dart
+++ b/mojo/dart/packages/mojo_services/lib/nfc/nfc.mojom.dart
@@ -508,11 +508,14 @@ const int _NfcTransmission_cancelName = 0;
 
 
 class _NfcTransmissionServiceDescription 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 NfcTransmission {
@@ -682,8 +685,13 @@ class NfcTransmissionStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _NfcTransmissionServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _NfcTransmissionServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }
 
 const int _NfcReceiver_onReceivedNfcDataName = 0;
@@ -691,11 +699,14 @@ const int _NfcReceiver_onReceivedNfcDataName = 0;
 
 
 class _NfcReceiverServiceDescription 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 NfcReceiver {
@@ -866,8 +877,13 @@ class NfcReceiverStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _NfcReceiverServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _NfcReceiverServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }
 
 const int _Nfc_transmitOnNextConnectionName = 0;
@@ -877,11 +893,14 @@ const int _Nfc_unregisterName = 2;
 
 
 class _NfcServiceDescription 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 Nfc {
@@ -1123,8 +1142,13 @@ class NfcStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
-    new _NfcServiceDescription();
+  static service_describer.ServiceDescription _cachedServiceDescription;
+  static service_describer.ServiceDescription get serviceDescription {
+    if (_cachedServiceDescription == null) {
+      _cachedServiceDescription = new _NfcServiceDescription();
+    }
+    return _cachedServiceDescription;
+  }
 }