Fix an issue that we didn't clean url request properly.

content/browser/download/download_item_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_ITEM_IMPL_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 215 matching lines @@
                               std::unique_ptr<crypto::SecureHash> hash_state);
 
   // Called by SavePackage to display progress when the DownloadItem
   // should be considered complete.
   virtual void MarkAsComplete();
 
   // DownloadDestinationObserver
   void DestinationUpdate(
       int64_t bytes_so_far,
       int64_t bytes_per_sec,
-      const std::vector<DownloadItem::ReceivedSlice>& received_slices) override;
+      const std::vector<DownloadItem::ReceivedSlice>& received_slices,
+      const std::unordered_set<int64_t>& stream_to_close) override;

[qinmin, 2017/04/14 20:04:43]

I would use finished_stream_offsets instead of stream_to_close for 2 reasons:
1. the param is offset, not streams.
2. these streams are considered finished.

[xingliu, 2017/04/15 00:26:29]

Done, changed to use a callback.

Callback looks cleaner than passing the offset here, thanks for the suggestion.

   void DestinationError(
       DownloadInterruptReason reason,
       int64_t bytes_so_far,
       std::unique_ptr<crypto::SecureHash> hash_state) override;
   void DestinationCompleted(
       int64_t total_bytes,
       std::unique_ptr<crypto::SecureHash> hash_state) override;
 
  private:
   friend class DownloadJob;
@@ skipping 464 matching lines @@
   std::unique_ptr<DownloadJob> job_;
 
   base::WeakPtrFactory<DownloadItemImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadItemImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_