[Popular Sites] Split PopularSites interface and PopularSitesImpl

ios/chrome/browser/prefs/browser_prefs.mm

 // 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/prefs/browser_prefs.h"
 
 #include "components/autofill/core/browser/autofill_manager.h"
 #include "components/browsing_data/core/pref_names.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/dom_distiller/core/distilled_page_prefs.h"
@@ skipping 75 matching lines @@
   autofill::AutofillManager::RegisterProfilePrefs(registry);
   dom_distiller::DistilledPagePrefs::RegisterProfilePrefs(registry);
   FirstRun::RegisterProfilePrefs(registry);
   gcm::GCMChannelStatusSyncer::RegisterProfilePrefs(registry);
   HostContentSettingsMap::RegisterProfilePrefs(registry);
   HttpServerPropertiesManagerFactory::RegisterProfilePrefs(registry);
   ntp_snippets::BookmarkSuggestionsProvider::RegisterProfilePrefs(registry);
   ntp_snippets::RemoteSuggestionsProvider::RegisterProfilePrefs(registry);
   ntp_snippets::ContentSuggestionsService::RegisterProfilePrefs(registry);
   ntp_tiles::MostVisitedSites::RegisterProfilePrefs(registry);
-  ntp_tiles::PopularSites::RegisterProfilePrefs(registry);
+  ntp_tiles::PopularSitesImpl::RegisterProfilePrefs(registry);
   ios::NotificationPromo::RegisterProfilePrefs(registry);
   password_manager::PasswordManager::RegisterProfilePrefs(registry);
   PrefProxyConfigTrackerImpl::RegisterProfilePrefs(registry);
   syncer::SyncPrefs::RegisterProfilePrefs(registry);
   TemplateURLPrepopulateData::RegisterProfilePrefs(registry);
   translate::TranslatePrefs::RegisterProfilePrefs(registry);
   variations::VariationsService::RegisterProfilePrefs(registry);
   ZeroSuggestProvider::RegisterProfilePrefs(registry);
   RegisterVoiceSearchBrowserStatePrefs(registry);
 
@@ skipping 40 matching lines @@
 }
 
 // This method should be periodically pruned of year+ old migrations.
 void MigrateObsoleteBrowserStatePrefs(PrefService* prefs) {
   // Added 07/2014.
   translate::TranslatePrefs::MigrateUserPrefs(prefs, prefs::kAcceptLanguages);
 
   // Added 08/2015.
   prefs->ClearPref(::prefs::kSigninSharedAuthenticationUserId);
 }