When adding a supervised user, ensure the shelf position is at the bottom.

chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc

Index: chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc
diff --git a/chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc b/chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc
index 3370ac903abb920e40c1d5a9b124d0a7ef7d04f7..f34493d86674014b10def3d519c3049cad964b21 100644
--- a/chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc
+++ b/chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc
@@ -20,6 +20,7 @@
 #include "chrome/browser/chromeos/login/supervised/supervised_user_creation_controller.h"
 #include "chrome/browser/chromeos/login/supervised/supervised_user_creation_controller_new.h"
 #include "chrome/browser/chromeos/login/supervised/supervised_user_creation_flow.h"
+#include "chrome/browser/chromeos/login/ui/login_display_host.h"
 #include "chrome/browser/chromeos/login/users/avatar/user_image_manager.h"
 #include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
 #include "chrome/browser/chromeos/login/users/supervised_user_manager.h"
@@ -374,6 +375,13 @@ void SupervisedUserCreationScreen::OnManagerFullyAuthenticated(
   ash::Shell::GetInstance()->
       desktop_background_controller()->MoveDesktopToLockedContainer();
 
+  // Hide the status area and the control bar, since they will show up at the
+  // logged in users's preferred location, which could be on the left or right
+  // side of the screen.
+  LoginDisplayHost* default_host = LoginDisplayHost::default_host();
+  default_host->SetStatusAreaVisible(false);
+  default_host->GetOobeUI()->GetCoreOobeActor()->ShowControlBar(false);
+
   controller_->SetManagerProfile(manager_profile);
   if (actor_)
     actor_->ShowUsernamePage();