Move shell service to toplevel shell namespace

components/mus/main.cc

Index: components/mus/main.cc
diff --git a/components/mus/main.cc b/components/mus/main.cc
index 134bb7221c3ee17ce7105e193a0c103f3282343a..3486f41897eed60e636910399b84087a50fdc5e8 100644
--- a/components/mus/main.cc
+++ b/components/mus/main.cc
@@ -7,7 +7,7 @@
 #include "services/shell/public/cpp/application_runner.h"
 
 MojoResult MojoMain(MojoHandle shell_handle) {
-  mojo::ApplicationRunner runner(new mus::MandolineUIServicesApp);
+  shell::ApplicationRunner runner(new mus::MandolineUIServicesApp);
   runner.set_message_loop_type(base::MessageLoop::TYPE_UI);
   return runner.Run(shell_handle);
 }