Revert of 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 657d9676d1571813873d9f04d25cc7551baa2fb9..a2400ec9a3a33d43e49760fa08b80572309c10b4 100644
--- a/mojo/shell/tests/lifecycle/app_client.cc
+++ b/mojo/shell/tests/lifecycle/app_client.cc
@@ -18,6 +18,10 @@
 bool AppClient::AcceptConnection(mojo::Connection* connection) {
   connection->AddInterface<LifecycleControl>(this);
   return true;
+}
+
+void AppClient::ShellConnectionLost() {
+  GracefulQuit();
 }
 
 void AppClient::Create(mojo::Connection* connection,