Enable device disabling during normal operation

chrome/browser/chromeos/login/screens/device_disabled_screen.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/login/screens/device_disabled_screen.h"
 
 #include <string>
 
 #include "base/logging.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_platform_part.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
-#include "chrome/browser/chromeos/system/device_disabling_manager.h"
 
 namespace chromeos {
 
 DeviceDisabledScreen::DeviceDisabledScreen(
     BaseScreenDelegate* base_screen_delegate,
     DeviceDisabledScreenActor* actor)
     : BaseScreen(base_screen_delegate),
-      showing_(false),
-      actor_(actor) {
+      actor_(actor),
+      device_disabling_manager_(g_browser_process->platform_part()->
+                                    device_disabling_manager()),
+      showing_(false) {
   DCHECK(actor_);
   if (actor_)
     actor_->SetDelegate(this);
+  device_disabling_manager_->AddObserver(this);
 }
 
 DeviceDisabledScreen::~DeviceDisabledScreen() {
   if (actor_)
     actor_->SetDelegate(nullptr);
+  device_disabling_manager_->RemoveObserver(this);
 }
 
 void DeviceDisabledScreen::PrepareToShow() {
 }
 
 void DeviceDisabledScreen::Show() {
   if (!actor_ || showing_)
     return;
 
   showing_ = true;
-  actor_->Show(g_browser_process->platform_part()->device_disabling_manager()->
-                  disabled_message());
+  actor_->Show(device_disabling_manager_->disabled_message());
 }
 
 void DeviceDisabledScreen::Hide() {
   if (!showing_)
     return;
   showing_ = false;
 
   if (actor_)
     actor_->Hide();
 }
 
 std::string DeviceDisabledScreen::GetName() const {
   return WizardController::kDeviceDisabledScreenName;
 }
 
 void DeviceDisabledScreen::OnActorDestroyed(DeviceDisabledScreenActor* actor) {
   if (actor_ == actor)
     actor_ = nullptr;
 }
 
+void DeviceDisabledScreen::OnDisabledMessageChanged(
+    const std::string& disabled_message) {
+  if (actor_)
+    actor_->UpdateMessage(disabled_message);
+}
+
 }  // namespace chromeos