[Downloads] Rework how hashes are calculated for download files.

content/browser/download/download_manager_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_IMPL_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_IMPL_H_
 
 #include <stdint.h>
 
 #include <set>
@@ skipping 77 matching lines @@
       const std::vector<GURL>& url_chain,
       const GURL& referrer_url,
       const std::string& mime_type,
       const std::string& original_mime_type,
       const base::Time& start_time,
       const base::Time& end_time,
       const std::string& etag,
       const std::string& last_modified,
       int64_t received_bytes,
       int64_t total_bytes,
+      const std::string& hash,
       content::DownloadItem::DownloadState state,
       DownloadDangerType danger_type,
       DownloadInterruptReason interrupt_reason,
       bool opened) override;
   int InProgressCount() const override;
   int NonMaliciousInProgressCount() const override;
   BrowserContext* GetBrowserContext() const override;
   void CheckForHistoryFilesRemoval() override;
   DownloadItem* GetDownload(uint32_t id) override;
 
@@ skipping 100 matching lines @@
       url_downloaders_;
 
   base::WeakPtrFactory<DownloadManagerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadManagerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_IMPL_H_