Cascade shutdown of instances

mash/init/init.h

Index: mash/init/init.h
diff --git a/mash/init/init.h b/mash/init/init.h
index b650f5032d2c9fc91628efaaba4380a7a20efa73..452b08985dd89c8ace0848885c8919608d37934f 100644
--- a/mash/init/init.h
+++ b/mash/init/init.h
@@ -43,13 +43,16 @@ class Init : public mojo::ShellClient,
                     const mojo::String& user_id) override;
   void StopServicesForUser(const mojo::String& user_id) override;
 
+  void UserServiceQuit(const std::string& user_id);
+
+  void StartTracing();
+  void StartResourceProvider();
   void StartLogin();
 
   mojo::Connector* connector_;
   scoped_ptr<mojo::Connection> login_connection_;
   mojo::BindingSet<mojom::Init> init_bindings_;
   std::map<std::string, scoped_ptr<mojo::Connection>> user_services_;
-  const std::string login_user_id_;
 
   DISALLOW_COPY_AND_ASSIGN(Init);
 };