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

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

Index: chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc
index db6ab4e59b16e7a59682e843c2346b3ce831e5da..2fc6069c36a89a313f35a0f73b373a0a1e9c2db2 100644
--- a/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc
@@ -87,8 +87,12 @@ void BaseScreenHandler::ShowScreenWithData(OobeScreen screen,
                                          screen_params);
 }
 
+OobeUI* BaseScreenHandler::GetOobeUI() const {
+  return static_cast<OobeUI*>(web_ui()->GetController());
+}
+
 OobeScreen BaseScreenHandler::GetCurrentScreen() const {
-  OobeUI* oobe_ui = static_cast<OobeUI*>(web_ui()->GetController());
+  OobeUI* oobe_ui = GetOobeUI();
   if (!oobe_ui)
     return OobeScreen::SCREEN_UNKNOWN;
   return oobe_ui->current_screen();