drive: Stop using /dev/null to store an empty file to the cache from CreateFileOperation

chrome/browser/chromeos/drive/job_scheduler.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/chromeos/drive/job_scheduler.h"
 
 #include <math.h>
 
 #include "base/message_loop.h"
 #include "base/prefs/pref_service.h"
@@ skipping 563 matching lines @@
 
 void JobScheduler::CreateFile(
     const std::string& parent_resource_id,
     const base::FilePath& drive_file_path,
     const std::string& title,
     const std::string& content_type,
     const DriveClientContext& context,
     const google_apis::GetResourceEntryCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  const base::FilePath kDevNull(FILE_PATH_LITERAL("/dev/null"));
+
   JobEntry* new_job = CreateNewJob(TYPE_CREATE_FILE);
   new_job->job_info.file_path = drive_file_path;
   new_job->context = context;
 
   UploadNewFileParams params;
   params.parent_resource_id = parent_resource_id;
   params.drive_file_path = drive_file_path;
-  params.local_file_path = base::FilePath(util::kSymLinkToDevNull);
+  params.local_file_path = kDevNull;  // Upload an empty file.
   params.title = title;
   params.content_type = content_type;
 
   ResumeUploadParams resume_params;
   resume_params.drive_file_path = params.drive_file_path;
   resume_params.local_file_path = params.local_file_path;
   resume_params.content_type = params.content_type;
 
   params.callback = base::Bind(&JobScheduler::OnUploadCompletionJobDone,
                                weak_ptr_factory_.GetWeakPtr(),
@@ skipping 354 matching lines @@
     case FILE_QUEUE:
       return "FILE_QUEUE";
     case NUM_QUEUES:
       break;  // This value is just a sentinel. Should never be used.
   }
   NOTREACHED();
   return "";
 }
 
 }  // namespace drive