[sync] skeleton implementation of TypedURLSyncBridge

components/history/core/browser/history_service.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.
 
 // 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 216 matching lines @@
   ScheduleTask(PRIORITY_NORMAL,
                base::Bind(&HistoryBackend::ClearCachedDataForContextID,
                           history_backend_, context_id));
 }
 
 URLDatabase* HistoryService::InMemoryDatabase() {
   DCHECK(thread_checker_.CalledOnValidThread());
   return in_memory_backend_ ? in_memory_backend_->db() : nullptr;
 }
 
+TypedURLSyncBridge* HistoryService::GetTypedURLSyncBridge() const {
+  return history_backend_->GetTypedURLSyncBridge();
+}
+
 TypedUrlSyncableService* HistoryService::GetTypedUrlSyncableService() const {
   return history_backend_->GetTypedUrlSyncableService();
 }
 
 void HistoryService::Shutdown() {
   DCHECK(thread_checker_.CalledOnValidThread());
   Cleanup();
 }
 
 void HistoryService::SetKeywordSearchTermsForURL(const GURL& url,
@@ skipping 902 matching lines @@
   return favicon_changed_callback_list_.Add(callback);
 }
 
 void HistoryService::NotifyFaviconsChanged(const std::set<GURL>& page_urls,
                                            const GURL& icon_url) {
   DCHECK(thread_checker_.CalledOnValidThread());
   favicon_changed_callback_list_.Notify(page_urls, icon_url);
 }
 
 }  // namespace history