The User Manager should be backed by a special profile, not the guest one.

chrome/browser/ui/views/profiles/user_manager_view.cc

Index: chrome/browser/ui/views/profiles/user_manager_view.cc
diff --git a/chrome/browser/ui/views/profiles/user_manager_view.cc b/chrome/browser/ui/views/profiles/user_manager_view.cc
index 5d305a76e502752c1aae48bd8cc989555e156628..9606516fef18f8cb453bca3a5a2fcabd62c25f7c 100644
--- a/chrome/browser/ui/views/profiles/user_manager_view.cc
+++ b/chrome/browser/ui/views/profiles/user_manager_view.cc
@@ -81,12 +81,12 @@ void UserManagerView::Show(const base::FilePath& profile_path_to_focus,
     return;
   }
 
-  // Create the guest profile, if necessary, and open the user manager
-  // from the guest profile.
-  profiles::CreateGuestProfileForUserManager(
+  // Create the User Manager profile, if necessary, and open the User Manager
+  // when the profile is ready.
+  profiles::CreateUserManagerProfile(
       profile_path_to_focus,
       tutorial_mode,
-      base::Bind(&UserManagerView::OnGuestProfileCreated));
+      base::Bind(&UserManagerView::OnUserManagerProfileCreated));
 }
 
 // static
@@ -101,9 +101,9 @@ bool UserManagerView::IsShowing() {
 }
 
 // static
-void UserManagerView::OnGuestProfileCreated(Profile* guest_profile,
-                                            const std::string& url) {
-  instance_ = new UserManagerView(guest_profile);
+void UserManagerView::OnUserManagerProfileCreated(Profile* profile,
+                                                  const std::string& url) {
+  instance_ = new UserManagerView(profile);
   DialogDelegate::CreateDialogWidget(instance_, NULL, NULL);
 
   gfx::NativeWindow window = instance_->GetWidget()->GetNativeWindow();
@@ -112,8 +112,7 @@ void UserManagerView::OnGuestProfileCreated(Profile* guest_profile,
 #if defined(OS_WIN)
   // Set the app id for the task manager to the app id of its parent
   ui::win::SetAppIdForWindow(
-      ShellIntegration::GetChromiumModelIdForProfile(
-          guest_profile->GetPath()),
+      ShellIntegration::GetChromiumModelIdForProfile(profile->GetPath()),
       views::HWNDForWidget(instance_->GetWidget()));
 #endif
   instance_->GetWidget()->Show();