drive: FileCache::Store marks the entry as dirty if empty MD5 is given

chrome/browser/chromeos/drive/file_system/download_operation.cc

 // Copyright 2013 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/file_system/download_operation.h"
 
-#include "base/callback_helpers.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/task_runner_util.h"
 #include "chrome/browser/chromeos/drive/drive.pb.h"
 #include "chrome/browser/chromeos/drive/file_cache.h"
 #include "chrome/browser/chromeos/drive/file_errors.h"
 #include "chrome/browser/chromeos/drive/file_system/operation_observer.h"
 #include "chrome/browser/chromeos/drive/file_system_util.h"
 #include "chrome/browser/chromeos/drive/job_scheduler.h"
@@ skipping 64 matching lines @@
       // This entry exists on the server, leave |cache_file_path| empty to
       // start download.
       return FILE_ERROR_OK;
     }
 
     // This entry does not exist on the server, store an empty file and mark it
     // as dirty.
     base::FilePath empty_file;
     if (!base::CreateTemporaryFileInDir(temporary_file_directory, &empty_file))
       return FILE_ERROR_FAILED;
-    error = cache->Store(local_id, base::MD5String(""), empty_file,
+    error = cache->Store(local_id, std::string(), empty_file,
                          internal::FileCache::FILE_OPERATION_MOVE);
     if (error != FILE_ERROR_OK)
       return error;
-    scoped_ptr<base::ScopedClosureRunner> file_closer;
-    error = cache->OpenForWrite(entry->local_id(), &file_closer);
-    if (error != FILE_ERROR_OK)
-      return error;
 
     if (!cache->GetCacheEntry(local_id, &cache_entry))
       return FILE_ERROR_NOT_FOUND;
   }
 
   // Leave |cache_file_path| empty when the stored file is obsolete and has no
   // local modification.
   if (!cache_entry.is_dirty() &&
       entry->file_specific_info().md5() != cache_entry.md5())
     return FILE_ERROR_OK;
@@ skipping 396 matching lines @@
   observer_->OnDirectoryChangedByOperation(file_path.DirName());
   params->OnComplete(*cache_file_path);
 }
 
 void DownloadOperation::CancelJob(JobID job_id) {
   scheduler_->CancelJob(job_id);
 }
 
 }  // namespace file_system
 }  // namespace drive