cros: Remove unused method

chrome/browser/ui/webui/chromeos/login/error_screen_handler.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_ERROR_SCREEN_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_ERROR_SCREEN_HANDLER_H_
 
 #include "base/macros.h"
 #include "chrome/browser/chromeos/login/screens/network_error_view.h"
 #include "chrome/browser/ui/webui/chromeos/login/base_screen_handler.h"
 #include "chrome/browser/ui/webui/chromeos/login/network_dropdown_handler.h"
 
 namespace chromeos {
 
 class NetworkErrorModel;
 
 // A class that handles the WebUI hooks in error screen.
 class ErrorScreenHandler : public BaseScreenHandler,
                            public NetworkErrorView,
                            public NetworkDropdownHandler::Observer {
  public:
   ErrorScreenHandler();
   ~ErrorScreenHandler() override;
 
   // ErrorView:
-  void PrepareToShow() override;
   void Show() override;
   void Hide() override;
   void Bind(NetworkErrorModel& model) override;
   void Unbind() override;
   void ShowOobeScreen(OobeScreen screen) override;
 
  private:
   // WebUI message handlers.
   void HandleHideCaptivePortal();
 
@@ skipping 18 matching lines @@
   bool showing_;
 
   base::WeakPtrFactory<ErrorScreenHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ErrorScreenHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_ERROR_SCREEN_HANDLER_H_