Revert of chromeos: Makes mushrome use simplified display management

ash/mus/main.cc

Index: ash/mus/main.cc
diff --git a/ash/mus/main.cc b/ash/mus/main.cc
index d152d516ddae2b8e4971ac774340d77210a75e62..e3aa4deb0463016855466afdf1b534f36a3a4d77 100644
--- a/ash/mus/main.cc
+++ b/ash/mus/main.cc
@@ -7,9 +7,6 @@
 #include "services/service_manager/public/cpp/service_runner.h"
 
 MojoResult ServiceMain(MojoHandle service_request_handle) {
-  const bool show_primary_host_on_connect = true;
-  ash::mus::WindowManagerApplication* app =
-      new ash::mus::WindowManagerApplication(show_primary_host_on_connect);
-  service_manager::ServiceRunner runner(app);
+  service_manager::ServiceRunner runner(new ash::mus::WindowManagerApplication);
   return runner.Run(service_request_handle);
 }