Revert 170483 - Remove PrefObserver usages, batch 12.

chrome/browser/ui/alternate_error_tab_observer.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/alternate_error_tab_observer.h"
 
 #include "chrome/browser/google/google_util.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 
 using content::RenderViewHost;
 using content::WebContents;
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(AlternateErrorPageTabObserver)
 
 AlternateErrorPageTabObserver::AlternateErrorPageTabObserver(
     WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       profile_(Profile::FromBrowserContext(web_contents->GetBrowserContext())) {
   PrefService* prefs = profile_->GetPrefs();
   if (prefs) {
     pref_change_registrar_.Init(prefs);
-    pref_change_registrar_.Add(
-        prefs::kAlternateErrorPagesEnabled,
-        base::Bind(&AlternateErrorPageTabObserver::
-                       OnAlternateErrorPagesEnabledChanged,
-                   base::Unretained(this)));
+    pref_change_registrar_.Add(prefs::kAlternateErrorPagesEnabled, this);
   }
 
   registrar_.Add(this, chrome::NOTIFICATION_GOOGLE_URL_UPDATED,
                  content::Source<Profile>(profile_->GetOriginalProfile()));
 }
 
 AlternateErrorPageTabObserver::~AlternateErrorPageTabObserver() {
 }
 
 // static
@@ skipping 15 matching lines @@
 
 void AlternateErrorPageTabObserver::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   DCHECK_EQ(chrome::NOTIFICATION_GOOGLE_URL_UPDATED, type);
   UpdateAlternateErrorPageURL(web_contents()->GetRenderViewHost());
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// PrefObserver overrides
+
+void AlternateErrorPageTabObserver::OnPreferenceChanged(
+    PrefServiceBase* service,
+    const std::string& pref_name) {
+  DCHECK_EQ(profile_->GetPrefs(), service);
+  DCHECK(prefs::kAlternateErrorPagesEnabled == pref_name);
+  UpdateAlternateErrorPageURL(web_contents()->GetRenderViewHost());
+}
+
+////////////////////////////////////////////////////////////////////////////////
 // Internal helpers
 
 GURL AlternateErrorPageTabObserver::GetAlternateErrorPageURL() const {
   GURL url;
   // Disable alternate error pages when in Incognito mode.
   if (profile_->IsOffTheRecord())
     return url;
 
   if (profile_->GetPrefs()->GetBoolean(prefs::kAlternateErrorPagesEnabled)) {
     url = google_util::LinkDoctorBaseURL();
     if (!url.is_valid())
       return url;
     url = google_util::AppendGoogleLocaleParam(url);
     url = google_util::AppendGoogleTLDParam(profile_, url);
   }
   return url;
 }
 
-void AlternateErrorPageTabObserver::OnAlternateErrorPagesEnabledChanged() {
-  UpdateAlternateErrorPageURL(web_contents()->GetRenderViewHost());
-}
-
 void AlternateErrorPageTabObserver::UpdateAlternateErrorPageURL(
     RenderViewHost* rvh) {
   rvh->SetAltErrorPageURL(GetAlternateErrorPageURL());
 }