cros: Cleanup lock screen and OOBE C++ backing code.

chrome/browser/chromeos/shutdown_policy_browsertest.cc

Index: chrome/browser/chromeos/shutdown_policy_browsertest.cc
diff --git a/chrome/browser/chromeos/shutdown_policy_browsertest.cc b/chrome/browser/chromeos/shutdown_policy_browsertest.cc
index 6c427f221e099e4d80fd4b8c6a44ece5d0760199..9ef134ab83d4bbaa4a3161cf152c0984eccd6c47 100644
--- a/chrome/browser/chromeos/shutdown_policy_browsertest.cc
+++ b/chrome/browser/chromeos/shutdown_policy_browsertest.cc
@@ -230,8 +230,7 @@ class ShutdownPolicyLockerTest : public ShutdownPolicyBaseTest {
     if (!tester->IsLocked())
       lock_state_observer.Wait();
     ScreenLocker* screen_locker = ScreenLocker::default_screen_locker();
-    WebUIScreenLocker* web_ui_screen_locker =
-        static_cast<WebUIScreenLocker*>(screen_locker->delegate());
+    WebUIScreenLocker* web_ui_screen_locker = screen_locker->web_ui();
     ASSERT_TRUE(web_ui_screen_locker);
     content::WebUI* web_ui = web_ui_screen_locker->GetWebUI();
     ASSERT_TRUE(web_ui);