chromeos: Break WebUILoginDisplay and SigninScreenHandler coupling on destruction.

chrome/browser/ui/webui/chromeos/login/signin_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/signin_screen_handler.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 270 matching lines @@
   CrosSettings::Get()->AddSettingsObserver(kAccountsPrefAllowNewUser, this);
   CrosSettings::Get()->AddSettingsObserver(kAccountsPrefAllowGuest, this);
 }
 
 SigninScreenHandler::~SigninScreenHandler() {
   weak_factory_.InvalidateWeakPtrs();
   if (cookie_remover_)
     cookie_remover_->RemoveObserver(this);
   if (key_event_listener_)
     key_event_listener_->RemoveCapsLockObserver(this);
+  if (delegate_)
+    delegate_->SetWebUIHandler(NULL);
   CrosSettings::Get()->RemoveSettingsObserver(kAccountsPrefAllowNewUser, this);
   CrosSettings::Get()->RemoveSettingsObserver(kAccountsPrefAllowGuest, this);
 }
 
 void SigninScreenHandler::GetLocalizedStrings(
     DictionaryValue* localized_strings) {
   localized_strings->SetString("signinScreenTitle",
       l10n_util::GetStringUTF16(IDS_SIGNIN_SCREEN_TITLE));
   localized_strings->SetString("signinScreenPasswordChanged",
       l10n_util::GetStringUTF16(IDS_SIGNIN_SCREEN_PASSWORD_CHANGED));
@@ skipping 228 matching lines @@
 
 void SigninScreenHandler::ShowGaiaPasswordChanged(const std::string& username) {
   email_ = username;
   password_changed_for_.insert(email_);
   base::StringValue email_value(email_);
   web_ui()->CallJavascriptFunction("cr.ui.Oobe.showSigninUI", email_value);
   web_ui()->CallJavascriptFunction(
       "login.AccountPickerScreen.updateUserGaiaNeeded", email_value);
 }
 
+void SigninScreenHandler::ResetSigninScreenHandlerDelegate() {
+  SetDelegate(NULL);
+}
+
 void SigninScreenHandler::OnBrowsingDataRemoverDone() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   cookie_remover_ = NULL;
   cookies_cleared_ = true;
   ShowSigninScreenIfReady();
 }
 
 void SigninScreenHandler::OnCapsLockChange(bool enabled) {
   if (page_is_ready()) {
     base::FundamentalValue capsLockState(enabled);
@@ skipping 460 matching lines @@
       !dns_clear_task_running_ &&
       network_state_informer_->is_online()) {
     gaia_silent_load_ = true;
     gaia_silent_load_network_ =
         network_state_informer_->active_network_service_path();
     LoadAuthExtension(true, true, false);
   }
 }
 
 }  // namespace chromeos