[Downloads] Rework how hashes are calculated for download files.

chrome/browser/download/download_history_unittest.cc

Index: chrome/browser/download/download_history_unittest.cc
diff --git a/chrome/browser/download/download_history_unittest.cc b/chrome/browser/download/download_history_unittest.cc
index 765588a8ddf463a4ef4114081c9c7ee5d8dc5a85..e10ffcbf5c3d253d1f0028c7eaf16ac57a81f702 100644
--- a/chrome/browser/download/download_history_unittest.cc
+++ b/chrome/browser/download/download_history_unittest.cc
@@ -236,19 +236,10 @@ class DownloadHistoryTest : public testing::Test {
     for (size_t index = 0; index < infos->size(); ++index) {
       const history::DownloadRow& row = infos->at(index);
       content::MockDownloadManager::CreateDownloadItemAdapter adapter(
-          history::ToContentDownloadId(row.id),
-          row.current_path,
-          row.target_path,
-          row.url_chain,
-          row.referrer_url,
-          row.mime_type,
-          row.original_mime_type,
-          row.start_time,
-          row.end_time,
-          row.etag,
-          row.last_modified,
-          row.received_bytes,
-          row.total_bytes,
+          history::ToContentDownloadId(row.id), row.current_path,
+          row.target_path, row.url_chain, row.referrer_url, row.mime_type,
+          row.original_mime_type, row.start_time, row.end_time, row.etag,
+          row.last_modified, row.received_bytes, row.total_bytes, std::string(),
           history::ToContentDownloadState(row.state),
           history::ToContentDownloadDangerType(row.danger_type),
           history::ToContentDownloadInterruptReason(row.interrupt_reason),