cros: Remove unused method

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/chromeos/login/update_screen_handler.h"
 
 #include <memory>
 
 #include "base/values.h"
 #include "chrome/browser/chromeos/login/screens/update_model.h"
@@ skipping 47 matching lines @@
   builder->Add("updatingScreenTitle", IDS_UPDATING_SCREEN_TITLE);
 }
 
 void UpdateScreenHandler::Initialize() {
   if (show_on_init_) {
     Show();
     show_on_init_ = false;
   }
 }
 
-void UpdateScreenHandler::PrepareToShow() {
-}
-
 void UpdateScreenHandler::Show() {
   if (!page_is_ready()) {
     show_on_init_ = true;
     return;
   }
   ShowScreen(OobeScreen::SCREEN_OOBE_UPDATE);
 }
 
 void UpdateScreenHandler::Hide() {
 }
 
 void UpdateScreenHandler::Bind(UpdateModel& model) {
   model_ = &model;
   BaseScreenHandler::SetBaseScreen(model_);
 }
 
 void UpdateScreenHandler::Unbind() {
   model_ = nullptr;
   BaseScreenHandler::SetBaseScreen(nullptr);
 }
 
 }  // namespace chromeos