Update VM service to new isolate API

tests/standalone/vmservice/test_helper.dart

Index: tests/standalone/vmservice/test_helper.dart
diff --git a/tests/standalone/vmservice/test_helper.dart b/tests/standalone/vmservice/test_helper.dart
index 815764851ede14c7e60357b1c725ef80841c7f2f..8e2b46ce1514036b9a249e2460d0b4222bb2ca2b 100644
--- a/tests/standalone/vmservice/test_helper.dart
+++ b/tests/standalone/vmservice/test_helper.dart
@@ -18,13 +18,13 @@ abstract class VmServiceRequestHelper {
       client = new HttpClient();
 
   Future makeRequest() {
+    print('** GET: $uri');
     return client.getUrl(uri)
       .then((HttpClientRequest request) => request.close())
       .then((HttpClientResponse response) {
         return response
             .fold(new BytesBuilder(), (b, d) => b..add(d))
             .then((builder) {
-              print('** GET: $uri');
               return _requestCompleted(builder.takeBytes(), response);
             });
       }).catchError((error) {