Remove unnecessary use_new_wrapper_types flag for some mojom targets.

services/service_manager/tests/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//services/service_manager/public/cpp/service.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 
 group("tests") {
   testonly = true
@@ skipping 22 matching lines @@
     "//services/service_manager/tests/service_manager",
     "//services/service_manager/tests/shutdown",
     "//testing/gtest",
   ]
 }
 
 mojom("interfaces") {
   sources = [
     "test.mojom",
   ]
-
-  use_new_wrapper_types = false
 }
 
 source_set("util") {
   sources = [
     "util.cc",
     "util.h",
   ]
   deps = [
     "//base",
     "//base:base_static",
     "//mojo/edk/system",
     "//services/service_manager/public/cpp:sources",
     "//services/service_manager/public/interfaces",
     "//services/service_manager/runner/common",
   ]
 }