WIP CallbackList in action

chrome/browser/ui/prefs/prefs_tab_helper.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/prefs/prefs_tab_helper.h"
 
 #include <string>
 
 #include "base/prefs/overlay_user_pref_store.h"
 #include "base/prefs/pref_service.h"
@@ skipping 447 matching lines @@
 #endif  // !defined(OS_ANDROID)
   }
 
   renderer_preferences_util::UpdateFromSystemSettings(
       web_contents_->GetMutableRendererPrefs(), GetProfile());
 
 #if !defined(OS_ANDROID)
   UserStyleSheetWatcher* uss =
       UserStyleSheetWatcherFactory::GetForProfile(GetProfile());
   if (uss) {
-    uss->RegisterOnStyleSheetUpdatedCallback(
+    remove_callback_ = uss->RegisterOnStyleSheetUpdatedCallback(
         base::Bind(&PrefsTabHelper::UpdateWebPreferences,
                    weak_ptr_factory_.GetWeakPtr()));
   }
 #endif
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && defined(ENABLE_THEMES)
   registrar_.Add(this, chrome::NOTIFICATION_BROWSER_THEME_CHANGED,
                  content::Source<ThemeService>(
                      ThemeServiceFactory::GetForProfile(GetProfile())));
 #endif
 #if defined(USE_AURA)
   registrar_.Add(this,
                  chrome::NOTIFICATION_BROWSER_FLING_CURVE_PARAMETERS_CHANGED,
                  content::NotificationService::AllSources());
 #endif
 }
 
 PrefsTabHelper::~PrefsTabHelper() {
+  remove_callback_.Run();
 }
 
 // static
 void PrefsTabHelper::InitIncognitoUserPrefStore(
     OverlayUserPrefStore* pref_store) {
   // List of keys that cannot be changed in the user prefs file by the incognito
   // profile.  All preferences that store information about the browsing history
   // or behavior of the user should have this property.
   pref_store->RegisterOverlayPref(prefs::kBrowserWindowPlacement);
   pref_store->RegisterOverlayPref(prefs::kSaveFileDefaultDirectory);
@@ skipping 217 matching lines @@
       WebPreferences web_prefs =
           web_contents_->GetRenderViewHost()->GetWebkitPreferences();
       OverrideFontFamily(&web_prefs, generic_family, script, std::string());
       web_contents_->GetRenderViewHost()->UpdateWebkitPreferences(web_prefs);
       return;
     }
   }
 
   UpdateWebPreferences();
 }