//chrome/browser/ui/ash/chrome_shell_delegate.cc

void InitAfterFirstSessionStart() {
  // Restore focus after the user session is started.  It's needed because some
  // windows can be opened in background while login UI is still active because
  // we currently restore browser windows before login UI is deleted.
  aura::Window::Windows mru_list =
      ash::Shell::Get()->mru_window_tracker()->BuildMruWindowList();
  if (!mru_list.empty())
    mru_list.front()->Focus();

  // Enable magnifier scroll keys as there may be no mouse cursor in kiosk mode.
  ash::MagnifierKeyScroller::SetEnabled(chrome::IsRunningInForcedAppMode());

  // Enable long press action to toggle spoken feedback with hotrod
  // remote which can't handle shortcut.
  ash::SpokenFeedbackToggler::SetEnabled(chrome::IsRunningInForcedAppMode());
}

Maybe a kiosk mode thing. Maybe it can use BrowserList instead of mru window list.