Remove TopSites::IsEnabled() as well as related dead code.

chrome/browser/history/history.cc

 // Copyright (c) 2010 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.
 
 // The history system runs on a background thread so that potentially slow
 // database operations don't delay the browser. This backend processing is
 // represented by HistoryBackend. The HistoryService's job is to dispatch to
 // that thread.
 //
 // Main thread                       History thread
@@ skipping 773 matching lines @@
     languages = prefs->GetString(prefs::kAcceptLanguages);
   }
   ScheduleAndForget(PRIORITY_UI, &HistoryBackend::Init, languages, no_db_);
 }
 
 void HistoryService::OnDBLoaded() {
   backend_loaded_ = true;
   NotificationService::current()->Notify(NotificationType::HISTORY_LOADED,
                                          Source<Profile>(profile_),
                                          Details<HistoryService>(this));
-  if (thread_ && profile_ && history::TopSites::IsEnabled()) {
+  if (thread_ && profile_) {
     // We don't want to force creation of TopSites.
     history::TopSites* ts = profile_->GetTopSitesWithoutCreating();
     if (ts)
       ts->HistoryLoaded();
   }
 }
 
 void HistoryService::StartTopSitesMigration() {
   needs_top_sites_migration_ = true;
-  if (thread_ && profile_ && history::TopSites::IsEnabled()) {
+  if (thread_ && profile_) {
     // We don't want to force creation of TopSites.
     history::TopSites* ts = profile_->GetTopSitesWithoutCreating();
     if (ts)
       ts->MigrateFromHistory();
   }
 }
 
 void HistoryService::OnTopSitesReady() {
   ScheduleAndForget(PRIORITY_NORMAL,
                     &HistoryBackend::MigrateThumbnailsDatabase);
 }