[sync] Clean up path generation for the local sync database.

ios/chrome/browser/sync/ios_chrome_sync_client.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/sync/ios_chrome_sync_client.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 168 matching lines @@
 syncer::SyncService* IOSChromeSyncClient::GetSyncService() {
   DCHECK_CURRENTLY_ON(web::WebThread::UI);
   return IOSChromeProfileSyncServiceFactory::GetForBrowserState(browser_state_);
 }
 
 PrefService* IOSChromeSyncClient::GetPrefService() {
   DCHECK_CURRENTLY_ON(web::WebThread::UI);
   return browser_state_->GetPrefs();
 }
 
+base::FilePath IOSChromeSyncClient::GetLocalSyncBackendFolder() {
+  return base::FilePath();
+}
+
 bookmarks::BookmarkModel* IOSChromeSyncClient::GetBookmarkModel() {
   DCHECK_CURRENTLY_ON(web::WebThread::UI);
   return ios::BookmarkModelFactory::GetForBrowserState(browser_state_);
 }
 
 favicon::FaviconService* IOSChromeSyncClient::GetFaviconService() {
   DCHECK_CURRENTLY_ON(web::WebThread::UI);
   return ios::FaviconServiceFactory::GetForBrowserState(
       browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
 }
@@ skipping 218 matching lines @@
         IOSChromeProfileSyncServiceFactory::GetForBrowserState(browser_state);
     if (profile_sync_service != nullptr) {
       const syncer::DeviceInfoTracker* tracker =
           profile_sync_service->GetDeviceInfoTracker();
       if (tracker != nullptr) {
         trackers->push_back(tracker);
       }
     }
   }
 }