Add new UMA stats for parallelizable download

content/browser/download/download_file_impl.h

Index: content/browser/download/download_file_impl.h
diff --git a/content/browser/download/download_file_impl.h b/content/browser/download/download_file_impl.h
index b3ce7d9259c8a57f2af114e9ef1ed22edc93719b..11c17df63cf05c421527b2b4a3fdd048f08d0c86 100644
--- a/content/browser/download/download_file_impl.h
+++ b/content/browser/download/download_file_impl.h
@@ -54,7 +54,8 @@ class CONTENT_EXPORT DownloadFileImpl : public DownloadFile {
 
   // DownloadFile functions.
   void Initialize(const InitializeCallback& callback,
-                  const DownloadItem::ReceivedSlices& received_slices) override;
+                  const DownloadItem::ReceivedSlices& received_slices,
+                  bool is_parallelizable) override;
 
   void AddByteStream(std::unique_ptr<ByteStreamReader> stream_reader,
                      int64_t offset,