Add support to sha256 hash the downloaded file....

chrome/browser/download/download_file.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/ref_counted.h"
 #include "chrome/browser/download/base_file.h"
 #include "chrome/browser/download/download_types.h"
 
 struct DownloadCreateInfo;
 class DownloadManager;
 class ResourceDispatcherHost;
 
 // These objects live exclusively on the download thread and handle the writing
 // operations for one download. These objects live only for the duration that
 // the download is 'in progress': once the download has been completed or
 // cancelled, the DownloadFile is destroyed.
 class DownloadFile : public BaseFile {
  public:
   DownloadFile(const DownloadCreateInfo* info,
-               DownloadManager* download_manager);
+               DownloadManager* download_manager,
+               bool calculate_hash);
   virtual ~DownloadFile();
 
   // Deletes its .crdownload intermediate file.
   // Marked virtual for testing.
   virtual void DeleteCrDownload();
 
   // Cancels the download request associated with this file.
   void CancelDownloadRequest(ResourceDispatcherHost* rdh);
 
   int id() const { return id_; }
@@ skipping 12 matching lines @@
   // Handle for informing the ResourceDispatcherHost of a UI based cancel.
   int request_id_;
 
   // DownloadManager this download belongs to.
   scoped_refptr<DownloadManager> download_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFile);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_