Add callback list to PrefModelAssociator after sync data is loaded

ios/chrome/browser/content_settings/host_content_settings_map_factory.cc

 // Copyright 2015 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 "ios/chrome/browser/content_settings/host_content_settings_map_factory.h"
 
 #include "base/memory/singleton.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "components/prefs/pref_service.h"
@@ skipping 26 matching lines @@
     web::BrowserState* context) const {
   ios::ChromeBrowserState* browser_state =
       ios::ChromeBrowserState::FromBrowserState(context);
   if (browser_state->IsOffTheRecord()) {
     // If off-the-record, retrieve the host content settings map of the parent
     // browser state to ensure the preferences have been migrated.
     GetForBrowserState(browser_state->GetOriginalChromeBrowserState());
   }
   return make_scoped_refptr(new HostContentSettingsMap(
       browser_state->GetPrefs(), browser_state->IsOffTheRecord(),
-      false /* guest_profile */));
+      false /* guest_profile */, nullptr /* PrefServiceSyncable* */));

[raymes, 2016/06/29 03:50:01]

nit: same here

[lshang, 2016/06/30 05:03:36]

Same as above, don't need to address this after we change to not pass in it.

 }
 
 web::BrowserState* HostContentSettingsMapFactory::GetBrowserStateToUse(
     web::BrowserState* context) const {
   return GetBrowserStateOwnInstanceInIncognito(context);
 }
 
 }  // namespace ios