chromeos: Break WebUILoginDisplay and SigninScreenHandler coupling on destruction.

chrome/browser/ui/webui/chromeos/login/signin_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_SIGNIN_SCREEN_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SIGNIN_SCREEN_HANDLER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 29 matching lines @@
   virtual void OnUserImageChanged(const User& user) = 0;
   virtual void OnPreferencesChanged() = 0;
   virtual void ShowError(int login_attempts,
                          const std::string& error_text,
                          const std::string& help_link_text,
                          HelpAppLauncher::HelpTopic help_topic_id) = 0;
   virtual void ShowGaiaPasswordChanged(const std::string& username) = 0;
   // Show siginin screen for the given credentials.
   virtual void ShowSigninScreenForCreds(const std::string& username,
                                         const std::string& password) = 0;
+  virtual void ResetSigninScreenHandlerDelegate() = 0;
  protected:
   virtual ~LoginDisplayWebUIHandler() {}
 };
 
 // An interface for SigninScreenHandler to call WebUILoginDisplay.
 class SigninScreenHandlerDelegate {
  public:
   // Confirms sign up by provided |username| and |password| specified.
   // Used for new user login via GAIA extension.
   virtual void CompleteLogin(const std::string& username,
@@ skipping 84 matching lines @@
   virtual void OnUserRemoved(const std::string& username) OVERRIDE;
   virtual void OnUserImageChanged(const User& user) OVERRIDE;
   virtual void OnPreferencesChanged() OVERRIDE;
   virtual void ShowError(int login_attempts,
                          const std::string& error_text,
                          const std::string& help_link_text,
                          HelpAppLauncher::HelpTopic help_topic_id) OVERRIDE;
   virtual void ShowSigninScreenForCreds(const std::string& username,
                                         const std::string& password) OVERRIDE;
   virtual void ShowGaiaPasswordChanged(const std::string& username) OVERRIDE;
+  virtual void ResetSigninScreenHandlerDelegate() OVERRIDE;
 
   // BrowsingDataRemover::Observer overrides.
   virtual void OnBrowsingDataRemoverDone() OVERRIDE;
 
   // SystemKeyEventListener::CapsLockObserver overrides.
   virtual void OnCapsLockChange(bool enabled) OVERRIDE;
 
   // content::NotificationObserver implementation.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
@@ skipping 106 matching lines @@
 
   // CapsLock state change notifier instance;
   SystemKeyEventListener* key_event_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(SigninScreenHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SIGNIN_SCREEN_HANDLER_H_