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

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

Index: chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
index 2516925aca9ae7e0e81c00db4ef1f9db33316843..fcc277cc43c532e5dd1e7842cfa880f9eaa088ec 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
@@ -37,6 +37,7 @@
 #include "chrome/browser/chromeos/login/error_screens_histogram_helper.h"
 #include "chrome/browser/chromeos/login/hwid_checker.h"
 #include "chrome/browser/chromeos/login/lock/screen_locker.h"
+#include "chrome/browser/chromeos/login/lock/webui_screen_locker.h"
 #include "chrome/browser/chromeos/login/quick_unlock/pin_storage.h"
 #include "chrome/browser/chromeos/login/quick_unlock/pin_storage_factory.h"
 #include "chrome/browser/chromeos/login/reauth_stats.h"
@@ -1230,8 +1231,9 @@ void SigninScreenHandler::HandleAccountPickerReady() {
 
 void SigninScreenHandler::HandleWallpaperReady() {
   if (ScreenLocker::default_screen_locker()) {
-    ScreenLocker::default_screen_locker()->delegate()->
-        OnLockBackgroundDisplayed();
+    ScreenLocker::default_screen_locker()
+        ->web_ui()
+        ->OnLockBackgroundDisplayed();
   }
 }