Revert 262846, as the revert has now been merged to M35.

trunk/src/chrome/browser/ui/alternate_error_tab_observer.h

Index: trunk/src/chrome/browser/ui/alternate_error_tab_observer.h
===================================================================
--- trunk/src/chrome/browser/ui/alternate_error_tab_observer.h	(revision 263955)
+++ trunk/src/chrome/browser/ui/alternate_error_tab_observer.h	(working copy)
@@ -1,61 +0,0 @@
-// 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_ALTERNATE_ERROR_TAB_OBSERVER_H_
-#define CHROME_BROWSER_UI_ALTERNATE_ERROR_TAB_OBSERVER_H_
-
-#include "base/prefs/pref_change_registrar.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "content/public/browser/web_contents_observer.h"
-#include "content/public/browser/web_contents_user_data.h"
-
-class Profile;
-
-namespace user_prefs {
-class PrefRegistrySyncable;
-}
-
-// Per-tab class to implement alternate error page functionality.
-class AlternateErrorPageTabObserver
-    : public content::WebContentsObserver,
-      public content::NotificationObserver,
-      public content::WebContentsUserData<AlternateErrorPageTabObserver> {
- public:
-  virtual ~AlternateErrorPageTabObserver();
-
-  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
-
- private:
-  explicit AlternateErrorPageTabObserver(content::WebContents* web_contents);
-  friend class content::WebContentsUserData<AlternateErrorPageTabObserver>;
-
-  // content::WebContentsObserver overrides:
-  virtual void RenderViewCreated(
-      content::RenderViewHost* render_view_host) OVERRIDE;
-
-  // content::NotificationObserver overrides:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  // Internal helpers ----------------------------------------------------------
-
-  // Returns the server that can provide alternate error pages.  If the returned
-  // URL is empty, the default error page built into WebKit will be used.
-  GURL GetAlternateErrorPageURL() const;
-
-  void OnAlternateErrorPagesEnabledChanged();
-
-  // Send the alternate error page URL to the renderer.
-  void UpdateAlternateErrorPageURL(content::RenderViewHost* rvh);
-
-  Profile* profile_;
-  content::NotificationRegistrar registrar_;
-  PrefChangeRegistrar pref_change_registrar_;
-
-  DISALLOW_COPY_AND_ASSIGN(AlternateErrorPageTabObserver);
-};
-
-#endif  // CHROME_BROWSER_UI_ALTERNATE_ERROR_TAB_OBSERVER_H_