Add device policy to disallow shutdown - ash UI modifications

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

Index: chrome/browser/ui/webui/chromeos/login/oobe_ui.h
diff --git a/chrome/browser/ui/webui/chromeos/login/oobe_ui.h b/chrome/browser/ui/webui/chromeos/login/oobe_ui.h
index b8ad9ca9e125fc1c9cf3955dbfa75e09ae3f728c..4938be597725e51c832fe4b78196e15a2cb49f32 100644
--- a/chrome/browser/ui/webui/chromeos/login/oobe_ui.h
+++ b/chrome/browser/ui/webui/chromeos/login/oobe_ui.h
@@ -15,6 +15,7 @@
 #include "base/observer_list.h"
 #include "chrome/browser/chromeos/login/ui/oobe_display.h"
 #include "chrome/browser/ui/webui/chromeos/login/core_oobe_handler.h"
+#include "chrome/browser/ui/webui/chromeos/login/shutdown_policy_observer.h"
 #include "content/public/browser/web_ui_controller.h"
 
 namespace base {
@@ -46,7 +47,8 @@ class UpdateScreenHandler;
 // - update screen.
 class OobeUI : public OobeDisplay,
                public content::WebUIController,
-               public CoreOobeHandler::Delegate {
+               public CoreOobeHandler::Delegate,
+               public ShutdownPolicyObserver::Delegate {
  public:
   class Observer {
    public:
@@ -125,6 +127,12 @@ class OobeUI : public OobeDisplay,
   DeviceDisabledScreenActor* GetDeviceDisabledScreenActor() override;
   virtual GaiaScreenHandler* GetGaiaScreenActor() override;
 
+  // Override from ShutdownPolicyObserver::Delegate.
+  virtual void OnShutdownPolicyChanged(bool reboot_on_shutdown) override;
+
+  // Initializes ShutdownPolicyObserver and triggers an initial update.
+  void InitShutdownPolicyObserver();
+
   // Collects localized strings from the owned handlers.
   void GetLocalizedStrings(base::DictionaryValue* localized_strings);
 
@@ -252,6 +260,9 @@ class OobeUI : public OobeDisplay,
   // List of registered observers.
   ObserverList<Observer> observer_list_;
 
+  // Observer of CrosSettings watching the kShutdownAllowed policy.
+  scoped_ptr<ShutdownPolicyObserver> shutdown_policy_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(OobeUI);
 };