cros: Remove unused method

chrome/browser/chromeos/login/screens/update_screen.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/chromeos/login/screens/update_screen.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
@@ skipping 303 matching lines @@
   if (!network_portal_detector::GetInstance()->IsEnabled()) {
     StartUpdateCheck();
     return;
   }
   state_ = STATE_FIRST_PORTAL_CHECK;
   is_first_detection_notification_ = true;
   is_first_portal_notification_ = true;
   network_portal_detector::GetInstance()->AddAndFireObserver(this);
 }
 
-void UpdateScreen::PrepareToShow() {
-  if (!view_)
-    return;
-
-  view_->PrepareToShow();
-}
-
 void UpdateScreen::Show() {
   is_shown_ = true;
   histogram_helper_->OnScreenShow();
 
 #if !defined(OFFICIAL_BUILD)
   GetContextEditor().SetBoolean(kContextKeyCancelUpdateShortcutEnabled, true);
 #endif
   GetContextEditor().SetInteger(kContextKeyProgress,
                                 kBeforeUpdateCheckProgress);
 
@@ skipping 261 matching lines @@
 }
 
 void UpdateScreen::OnConnectRequested() {
   if (state_ == STATE_ERROR) {
     LOG(WARNING) << "Hiding error message since AP was reselected";
     StartUpdateCheck();
   }
 }
 
 }  // namespace chromeos