Fix service test breakage

tests/standalone/vmservice/isolate_echo_test.dart

Index: tests/standalone/vmservice/isolate_echo_test.dart
diff --git a/tests/standalone/vmservice/isolate_echo_test.dart b/tests/standalone/vmservice/isolate_echo_test.dart
index d305248401ca0f038e5ae601650a0f922cd66e03..2f311d293a3d5c0c7562aa440ebb96ebd7b702da 100644
--- a/tests/standalone/vmservice/isolate_echo_test.dart
+++ b/tests/standalone/vmservice/isolate_echo_test.dart
@@ -14,22 +14,22 @@ class EchoRequestTest extends VmServiceRequestHelper {
   onRequestCompleted(Map reply) {
     Expect.equals('message', reply['type']);
 
-    Expect.equals(3, reply['message']['arguments'].length);
-    Expect.equals('_echo', reply['message']['arguments'][0]);
-    Expect.equals('foo', reply['message']['arguments'][1]);
-    Expect.equals('bar', reply['message']['arguments'][2]);
-
-    Expect.equals(4, reply['message']['option_keys'].length);
-    Expect.equals('a', reply['message']['option_keys'][0]);
-    Expect.equals('k', reply['message']['option_keys'][1]);
-    Expect.equals('d', reply['message']['option_keys'][2]);
-    Expect.equals('z', reply['message']['option_keys'][3]);
-
-    Expect.equals(4, reply['message']['option_values'].length);
-    Expect.equals('b', reply['message']['option_values'][0]);
-    Expect.equals('', reply['message']['option_values'][1]);
-    Expect.equals('e', reply['message']['option_values'][2]);
-    Expect.equals('w', reply['message']['option_values'][3]);
+    Expect.equals(3, reply['request']['arguments'].length);
+    Expect.equals('_echo', reply['request']['arguments'][0]);
+    Expect.equals('foo', reply['request']['arguments'][1]);
+    Expect.equals('bar', reply['request']['arguments'][2]);
+
+    Expect.equals(4, reply['request']['option_keys'].length);
+    Expect.equals('a', reply['request']['option_keys'][0]);
+    Expect.equals('k', reply['request']['option_keys'][1]);
+    Expect.equals('d', reply['request']['option_keys'][2]);
+    Expect.equals('z', reply['request']['option_keys'][3]);
+
+    Expect.equals(4, reply['request']['option_values'].length);
+    Expect.equals('b', reply['request']['option_values'][0]);
+    Expect.equals('', reply['request']['option_values'][1]);
+    Expect.equals('e', reply['request']['option_values'][2]);
+    Expect.equals('w', reply['request']['option_values'][3]);
   }
 }