Allow the powerwash shortcut only for devices without FRE

chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.h

Index: chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.h
diff --git a/chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.h b/chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.h
index b16deffebf0ebd082c80b1cc418cf4e4d547d59e..e903279e54f14a0b287cecb9711b3e389c063473 100644
--- a/chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.h
+++ b/chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.h
@@ -61,6 +61,18 @@ class AutoEnrollmentController {
   // build status.
   static Mode GetMode();
 
+  // Returns whether the auto-enrollment check is required. When
+  // kCheckEnrollmentKey VPD entry is present, it is explicitly stating whether
+  // the forced re-enrollment is required or not. Otherwise, for backward
+  // compatibility with devices upgrading from an older version of Chrome OS,
+  // the kActivateDateKey VPD entry is queried. If it's missing, FRE is not
+  // required. This enables factories to start full guest sessions for testing,
+  // see http://crbug.com/397354 for more context. The requirement for the
+  // machine serial number to be present is a sanity-check to ensure that the
+  // VPD has actually been read successfully. If VPD read failed, the FRE check
+  // is required.
+  static FRERequirement GetFRERequirement();

[achuithb, 2017/05/23 19:59:01]

Why not have:
bool IsForcedAutoEnrollmentRequired(). That way webui_login_view doesn't need to
know about NOT_REQUIRED and EXPLICITLY_NOT_REQUIRED, etc.

+
   AutoEnrollmentController();
   ~AutoEnrollmentController();