Remove DialogDelegate::UseNewStyle and unused code.

chrome/browser/ui/views/tab_modal_confirm_dialog_views.cc

Index: chrome/browser/ui/views/tab_modal_confirm_dialog_views.cc
diff --git a/chrome/browser/ui/views/tab_modal_confirm_dialog_views.cc b/chrome/browser/ui/views/tab_modal_confirm_dialog_views.cc
index 0c99fec4012dcc0945f68fb70683e2a476b7a9a3..d80d2031ad196857e3c7bf67ebc29dc799b7c293 100644
--- a/chrome/browser/ui/views/tab_modal_confirm_dialog_views.cc
+++ b/chrome/browser/ui/views/tab_modal_confirm_dialog_views.cc
@@ -15,7 +15,6 @@
 #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"
@@ -57,11 +56,8 @@ TabModalConfirmDialogViews::TabModalConfirmDialogViews(
       WebContentsModalDialogManager::FromWebContents(web_contents);
   WebContentsModalDialogManagerDelegate* modal_delegate =
       web_contents_modal_dialog_manager->delegate();
-  DCHECK(modal_delegate);

[sky, 2013/11/16 03:03:16]

and here.

[msw, 2013/11/16 04:15:44]

Done.

   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);
 }