Allow the initial request to take over failed parallel requests.

content/browser/download/download_file_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_FILE_IMPL_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_IMPL_H_
 
 #include "content/browser/download/download_file.h"
 
 #include <stddef.h>
@@ skipping 195 matching lines @@
   void AddNewSlice(int64_t offset, int64_t length);
 
   // Check if download is completed.
   bool IsDownloadCompleted();
 
   // Return the total valid bytes received in the target file.
   // If the file is a sparse file, return the total number of valid bytes.
   // Otherwise, return the current file size.
   int64_t TotalBytesReceived() const;
 
+  // Helper method to handle stream error
+  void HandleStreamError(SourceStream* source_stream,
+                         DownloadInterruptReason reason);
+
+  // Given a SourceStream object, returns its neighbor that preceds it if
+  // SourceStreams are ordered by their offsets
+  SourceStream* FindPrecedingNeighbor(SourceStream* source_stream);
+
   net::NetLogWithSource net_log_;
 
   // The base file instance.
   BaseFile file_;
 
   // DownloadSaveInfo provided during construction. Since the DownloadFileImpl
   // can be created on any thread, this holds the save_info_ until it can be
   // used to initialize file_ on the FILE thread.
   std::unique_ptr<DownloadSaveInfo> save_info_;
 
@@ skipping 30 matching lines @@
 
   base::WeakPtr<DownloadDestinationObserver> observer_;
   base::WeakPtrFactory<DownloadFileImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_IMPL_H_