Remove DialogDelegate::UseNewStyle and unused code.

chrome/browser/ui/views/tab_modal_confirm_dialog_views.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/views/tab_modal_confirm_dialog_views.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/tab_modal_confirm_dialog_delegate.h"
 #include "chrome/browser/ui/views/constrained_window_views.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/web_modal/web_contents_modal_dialog_host.h"
 #include "components/web_modal/web_contents_modal_dialog_manager.h"
 #include "components/web_modal/web_contents_modal_dialog_manager_delegate.h"
 #include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_view.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/window_open_disposition.h"
 #include "ui/views/controls/message_box_view.h"
 #include "ui/views/layout/layout_constants.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/dialog_client_view.h"
 
 using web_modal::WebContentsModalDialogManager;
 using web_modal::WebContentsModalDialogManagerDelegate;
@@ skipping 23 matching lines @@
   string16 link_text(delegate->GetLinkText());
   if (!link_text.empty())
     message_box_view_->SetLink(link_text, this);
 
   WebContentsModalDialogManager* web_contents_modal_dialog_manager =
       WebContentsModalDialogManager::FromWebContents(web_contents);
   WebContentsModalDialogManagerDelegate* modal_delegate =
       web_contents_modal_dialog_manager->delegate();
   DCHECK(modal_delegate);
   dialog_ = views::Widget::CreateWindowAsFramelessChild(
-      this,
-      web_contents->GetView()->GetNativeView(),
-      modal_delegate->GetWebContentsModalDialogHost()->GetHostView());
+      this, modal_delegate->GetWebContentsModalDialogHost()->GetHostView());
   web_contents_modal_dialog_manager->ShowDialog(dialog_->GetNativeView());
   delegate_->set_close_delegate(this);
 }
 
 TabModalConfirmDialogViews::~TabModalConfirmDialogViews() {
 }
 
 void TabModalConfirmDialogViews::AcceptTabModalDialog() {
   GetDialogClientView()->AcceptWindow();
 }
@@ skipping 71 matching lines @@
   delete this;
 }
 
 ui::ModalType TabModalConfirmDialogViews::GetModalType() const {
 #if defined(USE_ASH)
   return ui::MODAL_TYPE_CHILD;
 #else
   return views::WidgetDelegate::GetModalType();
 #endif
 }