Rewrite std::string("") to std::string(), Linux edition.

chrome/browser/sync_file_system/drive_file_sync_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.
 
 #include "chrome/browser/sync_file_system/drive_file_sync_service.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 393 matching lines @@
   }
 
   EnsureOriginRootDirectory(
       origin, base::Bind(&DriveFileSyncService::DidGetDriveDirectoryForOrigin,
                          AsWeakPtr(), base::Passed(&token), origin, callback));
 }
 
 void DriveFileSyncService::UnregisterOriginForTrackingChanges(
     const GURL& origin,
     const SyncStatusCallback& callback) {
-  scoped_ptr<TaskToken> token(GetToken(FROM_HERE, TASK_TYPE_DATABASE, ""));
+  scoped_ptr<TaskToken> token(
+      GetToken(FROM_HERE, TASK_TYPE_DATABASE, std::string()));
   if (!token) {
     pending_tasks_.push_back(base::Bind(
         &DriveFileSyncService::UnregisterOriginForTrackingChanges,
         AsWeakPtr(), origin, callback));
     return;
   }
 
   // TODO(nhiroki): Add helper function to forget remote changes for the given
   // origin like "ForgetRemoteChangesForOrigin(origin)".
   // http://crbug.com/211600
@@ skipping 10 matching lines @@
       &DriveFileSyncService::DidChangeOriginOnMetadataStore,
       AsWeakPtr(), base::Passed(&token), callback));
 }
 
 void DriveFileSyncService::EnableOriginForTrackingChanges(
     const GURL& origin,
     const SyncStatusCallback& callback) {
   if (!metadata_store_->IsOriginDisabled(origin))
     return;
 
-  scoped_ptr<TaskToken> token(GetToken(FROM_HERE, TASK_TYPE_DATABASE, ""));
+  scoped_ptr<TaskToken> token(
+      GetToken(FROM_HERE, TASK_TYPE_DATABASE, std::string()));
   if (!token) {
     pending_tasks_.push_back(base::Bind(
         &DriveFileSyncService::EnableOriginForTrackingChanges,
         AsWeakPtr(), origin, callback));
     return;
   }
 
   metadata_store_->EnableOrigin(origin, base::Bind(
       &DriveFileSyncService::DidChangeOriginOnMetadataStore,
       AsWeakPtr(), base::Passed(&token), callback));
   pending_batch_sync_origins_.insert(origin);
 }
 
 void DriveFileSyncService::DisableOriginForTrackingChanges(
     const GURL& origin,
     const SyncStatusCallback& callback) {
   if (!metadata_store_->IsBatchSyncOrigin(origin) &&
       !metadata_store_->IsIncrementalSyncOrigin(origin))
     return;
 
-  scoped_ptr<TaskToken> token(GetToken(FROM_HERE, TASK_TYPE_DATABASE, ""));
+  scoped_ptr<TaskToken> token(
+      GetToken(FROM_HERE, TASK_TYPE_DATABASE, std::string()));
   if (!token) {
     pending_tasks_.push_back(base::Bind(
         &DriveFileSyncService::DisableOriginForTrackingChanges,
         AsWeakPtr(), origin, callback));
     return;
   }
 
   // TODO(nhiroki): Add helper function to forget remote changes for the given
   // origin like "ForgetRemoteChangesForOrigin(origin)".
   // http://crbug.com/211600
@@ skipping 1999 matching lines @@
       pending_batch_sync_origins_.insert(origin);
   }
   callback.Run(status, resource_id);
 }
 
 std::string DriveFileSyncService::sync_root_resource_id() {
   return metadata_store_->sync_root_directory();
 }
 
 }  // namespace sync_file_system