Add device policy to disallow shutdown

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

+// 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.
+
+#ifndef CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SHUTDOWN_POLICY_OBSERVER_H_
+#define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SHUTDOWN_POLICY_OBSERVER_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/chromeos/settings/cros_settings.h"
+
+namespace chromeos {
+
+// This class observes the device setting "DeviceShutdownIsReboot". Changes to
+// this policy are communicated to the ShutdownPolicyObserver::Delegate by
+// calling its OnShutdownPolicyChanged method with the new state of the policy.
+class ShutdownPolicyObserver {
+ public:
+  using ShutdownIsRebootCallback = base::Callback<void(bool)>;

[bartfab (slow), 2014/12/08 16:49:45]

Nit 1: #include "base/callback_forward.h"
Nit 2: Document what this callback is for.

[cschuet (SLOW), 2014/12/08 18:57:04]

Done.

+
+  // This delegate is called when the "DeviceShutdownIsReboot" policy changes.
+  class Delegate {
+   public:
+    virtual void OnShutdownPolicyChanged(bool shutdown_allowed) = 0;

[bartfab (slow), 2014/12/08 16:49:45]

s/shutdown_allowed/shutdown_is_reboot/

[cschuet (SLOW), 2014/12/08 18:57:04]

Done.

+   protected:

[bartfab (slow), 2014/12/08 16:49:45]

Nit: Add a blank line above.

[cschuet (SLOW), 2014/12/08 18:57:04]

Done.

+    virtual ~Delegate() {}
+  };
+
+  ShutdownPolicyObserver(CrosSettings* cros_settings, Delegate* delegate);
+  ~ShutdownPolicyObserver();
+
+  void CheckIfShutdownIsReboot(const ShutdownIsRebootCallback& callback);

[bartfab (slow), 2014/12/08 16:49:45]

Nit: Add a comment that explains what this method does.

[cschuet (SLOW), 2014/12/08 18:57:04]

Done.

+
+  // Resets the policy subscription and clears the delegate.
+  void Shutdown();
+ private:

[bartfab (slow), 2014/12/08 16:49:45]

Niz: Add a blank line above.

[cschuet (SLOW), 2014/12/08 18:57:04]

Done.

+  void OnShutdownPolicyChanged();
+
+  CrosSettings* cros_settings_;
+
+  Delegate* delegate_;
+
+  scoped_ptr<CrosSettings::ObserverSubscription> shutdown_policy_subscription_;
+
+  base::WeakPtrFactory<ShutdownPolicyObserver> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShutdownPolicyObserver);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SHUTDOWN_POLICY_OBSERVER_H_