cros: Update ash when prefs related to lock are changed

chrome/browser/ui/ash/session_controller_client.cc

Index: chrome/browser/ui/ash/session_controller_client.cc
diff --git a/chrome/browser/ui/ash/session_controller_client.cc b/chrome/browser/ui/ash/session_controller_client.cc
index 6d15a762aa9f7a48b0bfe57ccdcb3f0207930ba6..96b2ab5ed037968162f884f0c96ee81aa8912970 100644
--- a/chrome/browser/ui/ash/session_controller_client.cc
+++ b/chrome/browser/ui/ash/session_controller_client.cc
@@ -26,6 +26,7 @@
 #include "chrome/grit/theme_resources.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
+#include "components/prefs/pref_change_registrar.h"
 #include "components/prefs/pref_service.h"
 #include "components/session_manager/core/session_manager.h"
 #include "content/public/browser/notification_service.h"
@@ -377,6 +378,18 @@ void SessionControllerClient::OnLoginUserProfilePrepared(Profile* profile) {
         ->AddObserver(this);
   }
 
+  base::Closure session_info_changed_closure =
+      base::Bind(&SessionControllerClient::SendSessionInfoIfChanged,
+                 weak_ptr_factory_.GetWeakPtr());
+  std::unique_ptr<PrefChangeRegistrar> pref_change_registrar =
+      base::MakeUnique<PrefChangeRegistrar>();
+  pref_change_registrar->Init(profile->GetPrefs());
+  pref_change_registrar->Add(prefs::kAllowScreenLock,
+                             session_info_changed_closure);
+  pref_change_registrar->Add(prefs::kEnableAutoScreenLock,
+                             session_info_changed_closure);
+  pref_change_registrars_.push_back(std::move(pref_change_registrar));
+
   // Needed because the user-to-profile mapping isn't available until later,
   // which is needed in UserToUserSession().
   base::ThreadTaskRunnerHandle::Get()->PostTask(