Clean-up of the system shutdown code paths

chrome/browser/ui/webui/chromeos/login/shutdown_policy_observer.cc

-// Copyright (c) 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/ui/webui/chromeos/login/shutdown_policy_observer.h"
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "chromeos/settings/cros_settings_names.h"
-#include "chromeos/settings/cros_settings_provider.h"
-
-namespace chromeos {
-
-ShutdownPolicyObserver::ShutdownPolicyObserver(CrosSettings* cros_settings,
-                                               Delegate* delegate)
-    : cros_settings_(cros_settings), delegate_(delegate), weak_factory_(this) {
-  if (delegate_) {
-    shutdown_policy_subscription_ = cros_settings_->AddSettingsObserver(
-        kRebootOnShutdown,
-        base::Bind(&ShutdownPolicyObserver::OnShutdownPolicyChanged,
-                   weak_factory_.GetWeakPtr()));
-  }
-}
-
-ShutdownPolicyObserver::~ShutdownPolicyObserver() {
-}
-
-void ShutdownPolicyObserver::Shutdown() {
-  shutdown_policy_subscription_.reset();
-  delegate_ = nullptr;
-}
-
-void ShutdownPolicyObserver::CallDelegate(bool reboot_on_shutdown) {
-  if (delegate_)
-    delegate_->OnShutdownPolicyChanged(reboot_on_shutdown);
-}
-
-void ShutdownPolicyObserver::OnShutdownPolicyChanged() {
-  CheckIfRebootOnShutdown(base::Bind(&ShutdownPolicyObserver::CallDelegate,
-                          weak_factory_.GetWeakPtr()));
-}
-
-void ShutdownPolicyObserver::CheckIfRebootOnShutdown(
-    const RebootOnShutdownCallback& callback) {
-  CrosSettingsProvider::TrustedStatus status =
-      cros_settings_->PrepareTrustedValues(
-          base::Bind(&ShutdownPolicyObserver::CheckIfRebootOnShutdown,
-                     weak_factory_.GetWeakPtr(), callback));
-  if (status != CrosSettingsProvider::TRUSTED)
-    return;
-
-  // Get the updated policy.
-  bool reboot_on_shutdown = false;
-  cros_settings_->GetBoolean(kRebootOnShutdown, &reboot_on_shutdown);
-  callback.Run(reboot_on_shutdown);
-}
-
-}  // namespace chromeos