Gets dart working with new Application::AcceptConnection param

services/dart/test/pingpong_target/main.dart

Index: services/dart/test/pingpong_target/main.dart
diff --git a/services/dart/test/pingpong_target/main.dart b/services/dart/test/pingpong_target/main.dart
index 5500322d69dab55ef456eeb011f1a7f801a38c12..96bc0ed661cba2731afbd7b878acbf91ed160726 100644
--- a/services/dart/test/pingpong_target/main.dart
+++ b/services/dart/test/pingpong_target/main.dart
@@ -43,7 +43,9 @@ class PingPongServiceImpl implements PingPongService {
 class PingPongApplication extends Application {
   PingPongApplication.fromHandle(MojoHandle handle) : super.fromHandle(handle);
 
-  void acceptConnection(String requestorUrl, ApplicationConnection connection) {
+  @override
+  void acceptConnection(String requestorUrl, String resolvedUrl,
+                        ApplicationConnection connection) {
     connection.provideService(PingPongServiceName,
         (endpoint) => new PingPongServiceImpl(this, endpoint));
     connection.listen();