Make DownloadFileImpl handle multiple byte streams.

content/browser/download/download_file_factory.cc

Index: content/browser/download/download_file_factory.cc
diff --git a/content/browser/download/download_file_factory.cc b/content/browser/download/download_file_factory.cc
index a2afc680a97dd2f1e3663b1a77451e7b3c98b8d5..a723c18e89ebc24c3318d9abf90cc9b64d0df187 100644
--- a/content/browser/download/download_file_factory.cc
+++ b/content/browser/download/download_file_factory.cc
@@ -18,10 +18,9 @@ DownloadFile* DownloadFileFactory::CreateFile(
     std::unique_ptr<ByteStreamReader> byte_stream,
     const net::NetLogWithSource& net_log,
     base::WeakPtr<DownloadDestinationObserver> observer) {
-  return new DownloadFileImpl(std::move(save_info),
-                              default_downloads_directory,
-                              std::move(byte_stream),
-                              net_log,
+  return new DownloadFileImpl(std::move(save_info), default_downloads_directory,
+                              std::move(byte_stream), net_log,
+                              false, /* is_sparse_file */
                               observer);
 }