Make Mandoline shut down cleanly.

mojo/services/network/url_loader_impl_apptest.cc

Index: mojo/services/network/url_loader_impl_apptest.cc
diff --git a/mojo/services/network/url_loader_impl_apptest.cc b/mojo/services/network/url_loader_impl_apptest.cc
index 583fd3d5a31c77aee232a77e0ac6626e00c21a25..1c4ec27192dd8b15be4c835f6c04ee3b0590a291 100644
--- a/mojo/services/network/url_loader_impl_apptest.cc
+++ b/mojo/services/network/url_loader_impl_apptest.cc
@@ -114,7 +114,9 @@ class UrlLoaderImplTest : public test::ApplicationTestBase {
     url_request_context->Init();
     network_context_.reset(new NetworkContext(url_request_context.Pass()));
     MessagePipe pipe;
-    new URLLoaderImpl(network_context_.get(), GetProxy(&url_loader_proxy_));
+    new URLLoaderImpl(network_context_.get(),
+                      GetProxy(&url_loader_proxy_),
+                      make_scoped_ptr<mojo::AppRefCount>(nullptr));
     EXPECT_TRUE(IsUrlLoaderValid());
   }