Remove PrefObserver usage, batch 3.

chrome/browser/content_settings/cookie_settings.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/content_settings/cookie_settings.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/content_settings/content_settings_utils.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/prefs/pref_service.h"
@@ skipping 77 matching lines @@
           prefs->GetBoolean(prefs::kBlockThirdPartyCookies)) {
   if (block_third_party_cookies_) {
     content::RecordAction(
         UserMetricsAction("ThirdPartyCookieBlockingEnabled"));
   } else {
     content::RecordAction(
         UserMetricsAction("ThirdPartyCookieBlockingDisabled"));
   }
 
   pref_change_registrar_.Init(prefs);
-  pref_change_registrar_.Add(prefs::kBlockThirdPartyCookies, this);
+  pref_change_registrar_.Add(
+      prefs::kBlockThirdPartyCookies,
+      base::Bind(&CookieSettings::OnBlockThirdPartyCookiesChanged,
+                 base::Unretained(this)));
 }
 
 ContentSetting
 CookieSettings::GetDefaultCookieSetting(std::string* provider_id) const {
   return host_content_settings_map_->GetDefaultContentSetting(
       CONTENT_SETTINGS_TYPE_COOKIES, provider_id);
 }
 
 bool CookieSettings::IsReadingCookieAllowed(const GURL& url,
                                             const GURL& first_party_url) const {
@@ skipping 39 matching lines @@
 }
 
 void CookieSettings::ResetCookieSetting(
     const ContentSettingsPattern& primary_pattern,
     const ContentSettingsPattern& secondary_pattern) {
   host_content_settings_map_->SetContentSetting(
       primary_pattern, secondary_pattern, CONTENT_SETTINGS_TYPE_COOKIES, "",
       CONTENT_SETTING_DEFAULT);
 }
 
-void CookieSettings::OnPreferenceChanged(PrefServiceBase* prefs,
-                                         const std::string& name) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(std::string(prefs::kBlockThirdPartyCookies), name);
-
-  base::AutoLock auto_lock(lock_);
-  block_third_party_cookies_ = prefs->GetBoolean(
-      prefs::kBlockThirdPartyCookies);
-}
-
 void CookieSettings::ShutdownOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   pref_change_registrar_.RemoveAll();
 }
 
 ContentSetting CookieSettings::GetCookieSetting(
     const GURL& url,
     const GURL& first_party_url,
     bool setting_cookie,
     content_settings::SettingSource* source) const {
@@ skipping 30 matching lines @@
       return CONTENT_SETTING_BLOCK;
   }
 
   // We should always have a value, at least from the default provider.
   DCHECK(value.get());
   return content_settings::ValueToContentSetting(value.get());
 }
 
 CookieSettings::~CookieSettings() {}
 
+void CookieSettings::OnBlockThirdPartyCookiesChanged() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  base::AutoLock auto_lock(lock_);
+  block_third_party_cookies_ = pref_change_registrar_.prefs()->GetBoolean(
+      prefs::kBlockThirdPartyCookies);
+}
+
 bool CookieSettings::ShouldBlockThirdPartyCookies() const {
   base::AutoLock auto_lock(lock_);
   return block_third_party_cookies_;
 }