chromeos: Break WebUILoginDisplay and SigninScreenHandler coupling on destruction.

chrome/browser/chromeos/login/webui_login_display.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/webui_login_display.h"
 
 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
 #include "chrome/browser/chromeos/input_method/input_method_manager.h"
 #include "chrome/browser/chromeos/input_method/xkeyboard.h"
 #include "chrome/browser/chromeos/login/webui_login_view.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/views/widget/widget.h"
 
 namespace chromeos {
 
 // WebUILoginDisplay, public: --------------------------------------------------
 
 WebUILoginDisplay::~WebUILoginDisplay() {
+  if (webui_handler_)
+    webui_handler_->ResetSigninScreenHandlerDelegate();
 }
 
 // LoginDisplay implementation: ------------------------------------------------
 
 WebUILoginDisplay::WebUILoginDisplay(LoginDisplay::Delegate* delegate)
     : LoginDisplay(delegate, gfx::Rect()),
       show_guest_(false),
       show_new_user_(false),
       webui_handler_(NULL) {
 }
@@ skipping 19 matching lines @@
 void WebUILoginDisplay::OnBeforeUserRemoved(const std::string& username) {
   for (UserList::iterator it = users_.begin(); it != users_.end(); ++it) {
     if ((*it)->email() == username) {
       users_.erase(it);
       break;
     }
   }
 }
 
 void WebUILoginDisplay::OnUserImageChanged(const User& user) {
-  DCHECK(webui_handler_);
-  webui_handler_->OnUserImageChanged(user);
+  if (webui_handler_)
+    webui_handler_->OnUserImageChanged(user);
 }
 
 void WebUILoginDisplay::OnUserRemoved(const std::string& username) {
-  DCHECK(webui_handler_);
-  webui_handler_->OnUserRemoved(username);
+  if (webui_handler_)
+    webui_handler_->OnUserRemoved(username);
 }
 
 void WebUILoginDisplay::OnFadeOut() {
 }
 
 void WebUILoginDisplay::OnLoginSuccess(const std::string& username) {
-  webui_handler_->OnLoginSuccess(username);
+  if (webui_handler_)
+    webui_handler_->OnLoginSuccess(username);
 }
 
 void WebUILoginDisplay::SetUIEnabled(bool is_enabled) {
-  if (is_enabled)
+  if (webui_handler_ && is_enabled)
     webui_handler_->ClearAndEnablePassword();
 }
 
 void WebUILoginDisplay::SelectPod(int index) {
 }
 
 void WebUILoginDisplay::ShowError(int error_msg_id,
                                   int login_attempts,
                                   HelpAppLauncher::HelpTopic help_topic_id) {
   VLOG(1) << "Show error, error_id: " << error_msg_id
           << ", attempts:" << login_attempts
           <<  ", help_topic_id: " << help_topic_id;
-  DCHECK(webui_handler_);
+  if (!webui_handler_)
+    return;
 
   std::string error_text;
   switch (error_msg_id) {
     case IDS_LOGIN_ERROR_AUTHENTICATING_HOSTED:
       error_text = l10n_util::GetStringFUTF8(
           error_msg_id, l10n_util::GetStringUTF16(IDS_PRODUCT_OS_NAME));
       break;
     case IDS_LOGIN_ERROR_CAPTIVE_PORTAL:
       error_text = l10n_util::GetStringFUTF8(
           error_msg_id, delegate()->GetConnectedNetworkName());
@@ skipping 28 matching lines @@
         help_link = l10n_util::GetStringUTF8(IDS_LEARN_MORE);
       break;
   }
 
   webui_handler_->ShowError(login_attempts, error_text, help_link,
                             help_topic_id);
   accessibility::MaybeSpeak(error_text);
 }
 
 void WebUILoginDisplay::ShowGaiaPasswordChanged(const std::string& username) {
-  webui_handler_->ShowGaiaPasswordChanged(username);
+  if (webui_handler_)
+    webui_handler_->ShowGaiaPasswordChanged(username);
 }
 
 // WebUILoginDisplay, SigninScreenHandlerDelegate implementation: --------------
 void WebUILoginDisplay::CompleteLogin(const std::string& username,
                                       const std::string& password) {
   DCHECK(delegate_);
   if (delegate_)
     delegate_->CompleteLogin(username, password);
 }
 
@@ skipping 36 matching lines @@
 }
 
 void WebUILoginDisplay::SetWebUIHandler(
     LoginDisplayWebUIHandler* webui_handler) {
   webui_handler_ = webui_handler;
 }
 
 void WebUILoginDisplay::ShowSigninScreenForCreds(
     const std::string& username,
     const std::string& password) {
-  DCHECK(webui_handler_);
-  webui_handler_->ShowSigninScreenForCreds(username, password);
+  if (webui_handler_)
+    webui_handler_->ShowSigninScreenForCreds(username, password);
 }
 
 const UserList& WebUILoginDisplay::GetUsers() const {
   return users_;
 }
 
 bool WebUILoginDisplay::IsShowGuest() const {
   return show_guest_;
 }
 
 bool WebUILoginDisplay::IsShowUsers() const {
   return show_users_;
 }
 
 bool WebUILoginDisplay::IsShowNewUser() const {
   return show_new_user_;
 }
 
 void WebUILoginDisplay::SetDisplayEmail(const std::string& email) {
   if (delegate_)
     delegate_->SetDisplayEmail(email);
 }
 
 }  // namespace chromeos