Cleanup: remove redundant tab close observation from TabModalConfirmDialogDelegate

chrome/browser/ui/tab_modal_confirm_dialog_delegate.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_TAB_MODAL_CONFIRM_DIALOG_DELEGATE_H_
 #define CHROME_BROWSER_UI_TAB_MODAL_CONFIRM_DIALOG_DELEGATE_H_
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/strings/string16.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 #include "ui/base/window_open_disposition.h"
 
 namespace content {
 class WebContents;
 }
 
 namespace gfx {
 class Image;
 }
 
 // Operations to be performed on the dialog by the
 // TabModalConfirmDialogDelegate.
 class TabModalConfirmDialogOperationsDelegate {
  public:
   TabModalConfirmDialogOperationsDelegate() {}
   virtual ~TabModalConfirmDialogOperationsDelegate() {}
 
   virtual void CloseDialog() = 0;
   virtual void SetPreventCloseOnLoadStart(bool prevent) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TabModalConfirmDialogOperationsDelegate);
 };
 
 // This class acts as the delegate for a simple tab-modal dialog confirming
 // whether the user wants to execute a certain action.
-class TabModalConfirmDialogDelegate : public content::NotificationObserver {
+class TabModalConfirmDialogDelegate {
  public:
-  explicit TabModalConfirmDialogDelegate(content::WebContents* web_contents);
+  TabModalConfirmDialogDelegate();
   virtual ~TabModalConfirmDialogDelegate();
 
   void set_operations_delegate(
       TabModalConfirmDialogOperationsDelegate* operations_delegate) {
     operations_delegate_ = operations_delegate;
   }
 
   // Accepts the confirmation prompt and calls |OnAccepted|.
   // This method is safe to call even from an |OnAccepted| or |OnCanceled|
   // callback.
@@ skipping 30 matching lines @@
   // The icons are only used on GTK. If these methods are not overriden,
   // the buttons have no stock icons.
   virtual const char* GetAcceptButtonIcon();
   virtual const char* GetCancelButtonIcon();
 
  protected:
   TabModalConfirmDialogOperationsDelegate* operations_delegate() {
     return operations_delegate_;
   }
 
-  // content::NotificationObserver implementation.
-  // Watch for a closed tab and dismiss the dialog if it occurs.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  content::NotificationRegistrar registrar_;
-
  private:
   // It is guaranteed that exactly one of |OnAccepted|, |OnCanceled| or
   // |OnLinkClicked| is eventually called. These method are private to
   // enforce this guarantee. Access to them is controlled by |Accept|,
   // |Cancel| and |LinkClicked|.
 
   // Called when the user accepts or cancels the dialog, respectively.
   virtual void OnAccepted();
   virtual void OnCanceled();
 
   // Called when the user clicks on the link (if any).
   virtual void OnLinkClicked(WindowOpenDisposition disposition);
 
   // Close the dialog.
   void CloseDialog();
 
   TabModalConfirmDialogOperationsDelegate* operations_delegate_;
   // True iff we are in the process of closing, to avoid running callbacks
   // multiple times.
   bool closing_;
 
   DISALLOW_COPY_AND_ASSIGN(TabModalConfirmDialogDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_TAB_MODAL_CONFIRM_DIALOG_DELEGATE_H_