Make ApplicationTestBase not use ApplicationImpl.

services/contacts/contacts_apptest.cc

Index: services/contacts/contacts_apptest.cc
diff --git a/services/contacts/contacts_apptest.cc b/services/contacts/contacts_apptest.cc
index 4a3cba2da8de958563044364aa72177776ba8e46..477da471f4ba9f84efb552a959f36eed8635e38a 100644
--- a/services/contacts/contacts_apptest.cc
+++ b/services/contacts/contacts_apptest.cc
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 #include "base/run_loop.h"
-#include "mojo/public/cpp/application/application_impl.h"
 #include "mojo/public/cpp/application/application_test_base.h"
 #include "mojo/public/cpp/application/connect.h"
 #include "mojo/services/contacts/interfaces/contacts.mojom.h"
@@ -17,7 +16,7 @@ class ContactAppTest : public mojo::test::ApplicationTestBase {
 
   void SetUp() override {
     mojo::test::ApplicationTestBase::SetUp();
-    mojo::ConnectToService(application_impl()->shell(), "mojo:contacts",
+    mojo::ConnectToService(shell(), "mojo:contacts",
                            GetProxy(&contacts_service_));
   }