Add a lock to the managed user settings page and require authentication for unlocking.

chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc

Index: chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
diff --git a/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc b/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
index 7b44b6b2b5ba5bdc5d1f5f0598c202ac05a75a97..4b583c5e6e93c1c988dc61778efe680a932f41f6 100644
--- a/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
+++ b/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
@@ -206,6 +206,8 @@ WebUIFactoryFunction GetWebUIFactoryFunction(WebUI* web_ui,
     return &NewWebUI<InstantUI>;
   if (url.host() == chrome::kChromeUILocalOmniboxPopupHost)
     return &NewWebUI<LocalOmniboxPopupUI>;
+  if (url.host() == chrome::kChromeUIManagedUserPassphrasePageHost)
+    return &NewWebUI<ConstrainedWebDialogUI>;
   if (url.host() == chrome::kChromeUIMediaInternalsHost)
     return &NewWebUI<MediaInternalsUI>;
 #if !defined(DISABLE_NACL)