Expose Service Describer in Dart mojo package

mojo/dart/packages/mojo_services/lib/mojo/ui/view_trees.mojom.dart

Index: mojo/dart/packages/mojo_services/lib/mojo/ui/view_trees.mojom.dart
diff --git a/mojo/dart/packages/mojo_services/lib/mojo/ui/view_trees.mojom.dart b/mojo/dart/packages/mojo_services/lib/mojo/ui/view_trees.mojom.dart
index 9cc565e69d658cc43eb7dbe207268f52b6945071..412b95c0d9ef086323444d104ecd255d0a21fb39 100644
--- a/mojo/dart/packages/mojo_services/lib/mojo/ui/view_trees.mojom.dart
+++ b/mojo/dart/packages/mojo_services/lib/mojo/ui/view_trees.mojom.dart
@@ -927,11 +927,14 @@ const int _ViewTree_onRootUnavailableName = 1;
 
 
 class _ViewTreeServiceDescription 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 ViewTree {
@@ -1198,7 +1201,7 @@ class ViewTreeStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
+  static service_describer.ServiceDescription get serviceDescription =>
     new _ViewTreeServiceDescription();
 }
 
@@ -1212,11 +1215,14 @@ const int _ViewTreeHost_layoutRootName = 5;
 
 
 class _ViewTreeHostServiceDescription 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 ViewTreeHost {
@@ -1545,7 +1551,7 @@ class ViewTreeHostStub extends bindings.Stub {
 
   int get version => 0;
 
-  service_describer.ServiceDescription get serviceDescription =>
+  static service_describer.ServiceDescription get serviceDescription =>
     new _ViewTreeHostServiceDescription();
 }