Disable token handle fetching on some devices

chrome/browser/chromeos/login/existing_user_controller.h

Index: chrome/browser/chromeos/login/existing_user_controller.h
diff --git a/chrome/browser/chromeos/login/existing_user_controller.h b/chrome/browser/chromeos/login/existing_user_controller.h
index 8fe0d6164e19e4995512765d4b7ea94be69a6c19..eea1471d577f449390b1d7cea5eac70e9f533773 100644
--- a/chrome/browser/chromeos/login/existing_user_controller.h
+++ b/chrome/browser/chromeos/login/existing_user_controller.h
@@ -247,6 +247,9 @@ class ExistingUserController : public LoginDisplay::Delegate,
   void OnTokenHandleObtained(const user_manager::UserID& id,
                              TokenHandleUtil::TokenHandleStatus status);
 
+  // Returns |true| if token handles should be used on this device.
+  bool TokenHandlesEnabled();
+
   // Public session auto-login timer.
   scoped_ptr<base::OneShotTimer<ExistingUserController> > auto_login_timer_;