Add checks to delegate in SigninScreenHandler

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

 // Copyright (c) 2011 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/command_line.h"
 #include "base/hash_tables.h"
@@ skipping 283 matching lines @@
       l10n_util::GetStringUTF16(IDS_CREATE_ACCOUNT_HTML));
   localized_strings->SetString("guestSignin",
       l10n_util::GetStringUTF16(IDS_BROWSE_WITHOUT_SIGNING_IN_HTML));
   localized_strings->SetString("removeUser",
       l10n_util::GetStringUTF16(IDS_LOGIN_REMOVE));
 
   localized_strings->SetString("authType", "ext");
 }
 
 void SigninScreenHandler::Show(bool oobe_ui) {
+  CHECK(delegate_);
+
   oobe_ui_ = oobe_ui;
   if (!page_is_ready()) {
     show_on_init_ = true;
     return;
   }
 
   if (oobe_ui) {
     // Shows new user sign-in for OOBE.
     HandleShowAddUser(NULL);
   } else {
     // Populates account picker. Animation is turned off for now until we
     // figure out how to make it fast enough.
     SendUserList(false);
 
     // Reset Caps Lock state when login screen is shown.
     input_method::InputMethodManager::GetInstance()->GetXKeyboard()->
         SetCapsLockEnabled(false);
 
     ShowScreen(kAccountPickerScreen, NULL);
   }
 }
 
 void SigninScreenHandler::SetDelegate(SigninScreenHandlerDelegate* delegate) {
+  CHECK(delegate);
   delegate_ = delegate;
-  DCHECK(delegate_);
   delegate_->SetWebUIHandler(this);
 }
 
 // SigninScreenHandler, private: -----------------------------------------------
 
 void SigninScreenHandler::Initialize() {
   // Register for Caps Lock state change notifications;
   key_event_listener_ = SystemKeyEventListener::GetInstance();
   if (key_event_listener_)
     key_event_listener_->AddCapsLockObserver(this);
@@ skipping 409 matching lines @@
 
   cookie_remover_ = new BrowsingDataRemover(
       Profile::FromBrowserContext(web_ui_->tab_contents()->browser_context()),
       BrowsingDataRemover::EVERYTHING,
       base::Time());
   cookie_remover_->AddObserver(this);
   cookie_remover_->Remove(BrowsingDataRemover::REMOVE_SITE_DATA);
 }
 
 }  // namespace chromeos