Quit the message loop by default in ShellConnectionLost when ApplicationRunner is used

mojo/shell/tests/lifecycle/app_client.cc

Index: mojo/shell/tests/lifecycle/app_client.cc
diff --git a/mojo/shell/tests/lifecycle/app_client.cc b/mojo/shell/tests/lifecycle/app_client.cc
index a2400ec9a3a33d43e49760fa08b80572309c10b4..657d9676d1571813873d9f04d25cc7551baa2fb9 100644
--- a/mojo/shell/tests/lifecycle/app_client.cc
+++ b/mojo/shell/tests/lifecycle/app_client.cc
@@ -20,10 +20,6 @@ bool AppClient::AcceptConnection(mojo::Connection* connection) {
   return true;
 }
 
-void AppClient::ShellConnectionLost() {
-  GracefulQuit();
-}
-
 void AppClient::Create(mojo::Connection* connection,
                        LifecycleControlRequest request) {
   bindings_.AddBinding(this, std::move(request));