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

content/browser/download/download_item_impl.h

Index: content/browser/download/download_item_impl.h
diff --git a/content/browser/download/download_item_impl.h b/content/browser/download/download_item_impl.h
index 9b4fe748f5efa6481daf7b55a75724fcea2e8eb1..a6dc044efb448b3e37452aed9f6460f8962d4456 100644
--- a/content/browser/download/download_item_impl.h
+++ b/content/browser/download/download_item_impl.h
@@ -233,7 +233,8 @@ class CONTENT_EXPORT DownloadItemImpl
   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,