cros: Remove unused method

chrome/browser/chromeos/login/screens/wrong_hwid_screen.cc

 // Copyright (c) 2013 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/chromeos/login/screens/wrong_hwid_screen.h"
 
 #include "chrome/browser/chromeos/login/screens/base_screen_delegate.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 
 namespace chromeos {
 
 WrongHWIDScreen::WrongHWIDScreen(BaseScreenDelegate* base_screen_delegate,
                                  WrongHWIDScreenActor* actor)
     : BaseScreen(base_screen_delegate), actor_(actor) {
   DCHECK(actor_);
   if (actor_)
     actor_->SetDelegate(this);
 }
 
 WrongHWIDScreen::~WrongHWIDScreen() {
   if (actor_)
     actor_->SetDelegate(NULL);
 }
 
-void WrongHWIDScreen::PrepareToShow() {
-  if (actor_)
-    actor_->PrepareToShow();
-}
-
 void WrongHWIDScreen::Show() {
   if (actor_)
     actor_->Show();
 }
 
 void WrongHWIDScreen::Hide() {
   if (actor_)
     actor_->Hide();
 }
 
 std::string WrongHWIDScreen::GetName() const {
   return WizardController::kWrongHWIDScreenName;
 }
 
 void WrongHWIDScreen::OnExit() {
   Finish(BaseScreenDelegate::WRONG_HWID_WARNING_SKIPPED);
 }
 
 void WrongHWIDScreen::OnActorDestroyed(WrongHWIDScreenActor* actor) {
   if (actor_ == actor)
     actor_ = NULL;
 }
 
 }  // namespace chromeos