Use PrefChangeRegistrar everywhere

chrome/browser/dom_ui/ntp_resource_cache.cc

 // Copyright (c) 2009 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/dom_ui/ntp_resource_cache.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "app/animation.h"
@@ skipping 115 matching lines @@
   return BrowserThemeProvider::TilingToString(repeat_mode);
 }
 
 }  // namespace
 
 NTPResourceCache::NTPResourceCache(Profile* profile) : profile_(profile) {
   registrar_.Add(this, NotificationType::BROWSER_THEME_CHANGED,
                  NotificationService::AllSources());
 
   // Watch for pref changes that cause us to need to invalidate the HTML cache.
-  PrefService* pref_service = profile_->GetPrefs();
-  pref_service->AddPrefObserver(prefs::kShowBookmarkBar, this);
-  pref_service->AddPrefObserver(prefs::kNTPShownSections, this);
-}
-
-NTPResourceCache::~NTPResourceCache() {
-  PrefService* pref_service = profile_->GetPrefs();
-  pref_service->RemovePrefObserver(prefs::kShowBookmarkBar, this);
-  pref_service->RemovePrefObserver(prefs::kNTPShownSections, this);
+  pref_change_registrar_.Init(profile_->GetPrefs());
+  pref_change_registrar_.Add(prefs::kShowBookmarkBar, this);
+  pref_change_registrar_.Add(prefs::kNTPShownSections, this);
 }
 
 RefCountedBytes* NTPResourceCache::GetNewTabHTML(bool is_off_the_record) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
   if (is_off_the_record) {
     if (!new_tab_incognito_html_.get())
       CreateNewTabIncognitoHTML();
   } else {
     if (!new_tab_html_.get())
       CreateNewTabHTML();
@@ skipping 330 matching lines @@
   std::string css_string;
   css_string = ReplaceStringPlaceholders(new_tab_theme_css, subst, NULL);
   css_string = ReplaceStringPlaceholders(css_string, subst2, NULL);
   css_string = ReplaceStringPlaceholders(css_string, subst3, NULL);
 
   new_tab_css_ = new RefCountedBytes;
   new_tab_css_->data.resize(css_string.size());
   std::copy(css_string.begin(), css_string.end(),
             new_tab_css_->data.begin());
 }