Add device policy to disallow shutdown - ash UI modifications

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

Index: chrome/browser/ui/webui/chromeos/login/core_oobe_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/core_oobe_handler.cc b/chrome/browser/ui/webui/chromeos/login/core_oobe_handler.cc
index a8a18f8e8bfbb57148325841aea2f706feea3a5a..70bae116997a2374998b8d59084e85db736f2761 100644
--- a/chrome/browser/ui/webui/chromeos/login/core_oobe_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/core_oobe_handler.cc
@@ -241,6 +241,9 @@ void CoreOobeHandler::SetClientAreaSize(int width, int height) {
 
 void CoreOobeHandler::HandleInitialized() {
   oobe_ui_->InitializeHandlers();
+
+  // Initialize the ShutdownPolicyObserver and trigger an initial update.
+  oobe_ui_->InitShutdownPolicyObserver();
 }
 
 void CoreOobeHandler::HandleSkipUpdateEnrollAfterEula() {
@@ -326,6 +329,11 @@ void CoreOobeHandler::ShowOobeUI(bool show) {
     UpdateOobeUIVisibility();
 }
 
+void CoreOobeHandler::UpdateShutdownButtonVisibility(
+    bool shutdown_button_visible) {
+  CallJS("showShutdown", shutdown_button_visible);
+}
+
 void CoreOobeHandler::UpdateA11yState() {
 #if !defined(USE_ATHENA)
   // TODO(dpolukhin): crbug.com/412891