Glue parallel download job and download file together.

content/public/browser/download_item.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.
 //
 // Each download is represented by a DownloadItem, and all DownloadItems
 // are owned by the DownloadManager which maintains a global list of all
 // downloads. DownloadItems are created when a user initiates a download,
 // and exist for the duration of the browser life time.
 //
 // Download observers:
@@ skipping 99 matching lines @@
         : offset(offset), received_bytes(received_bytes) {}
 
     bool operator==(const ReceivedSlice& rhs) const {
       return offset == rhs.offset && received_bytes == rhs.received_bytes;
     }
 
     int64_t offset;
     int64_t received_bytes;
   };
 
+  using ReceivedSlices = std::vector<DownloadItem::ReceivedSlice>;

[David Trainor- moved to gerrit, 2017/03/14 17:59:10]

Aha!

+
   ~DownloadItem() override {}
 
   // Observation ---------------------------------------------------------------
 
   virtual void AddObserver(DownloadItem::Observer* observer) = 0;
   virtual void RemoveObserver(DownloadItem::Observer* observer) = 0;
   virtual void UpdateObservers() = 0;
 
   // User Actions --------------------------------------------------------------
 
@@ skipping 304 matching lines @@
   // return |name|. Has no effect on the final target filename.
   virtual void SetDisplayName(const base::FilePath& name) = 0;
 
   // Debug/testing -------------------------------------------------------------
   virtual std::string DebugString(bool verbose) const = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_ITEM_H_