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

content/public/test/mock_download_manager.cc

Index: content/public/test/mock_download_manager.cc
diff --git a/content/public/test/mock_download_manager.cc b/content/public/test/mock_download_manager.cc
index 7e477f0567190eb69ace4a33f2c7a0f06ee2d142..1c381d514797136bc9344aad8a879b81f8230934 100644
--- a/content/public/test/mock_download_manager.cc
+++ b/content/public/test/mock_download_manager.cc
@@ -23,6 +23,7 @@ MockDownloadManager::CreateDownloadItemAdapter::CreateDownloadItemAdapter(
     const std::string& last_modified,
     int64_t received_bytes,
     int64_t total_bytes,
+    const std::string& hash,
     DownloadItem::DownloadState state,
     DownloadDangerType danger_type,
     DownloadInterruptReason interrupt_reason,
@@ -38,6 +39,7 @@ MockDownloadManager::CreateDownloadItemAdapter::CreateDownloadItemAdapter(
       end_time(end_time),
       received_bytes(received_bytes),
       total_bytes(total_bytes),
+      hash(hash),
       state(state),
       danger_type(danger_type),
       interrupt_reason(interrupt_reason),
@@ -109,15 +111,16 @@ DownloadItem* MockDownloadManager::CreateDownloadItem(
     const std::string& last_modified,
     int64_t received_bytes,
     int64_t total_bytes,
+    const std::string& hash,
     DownloadItem::DownloadState state,
     DownloadDangerType danger_type,
     DownloadInterruptReason interrupt_reason,
     bool opened) {
-  CreateDownloadItemAdapter adapter(
-      id, current_path, target_path, url_chain, referrer_url, mime_type,
-      original_mime_type, start_time, end_time, etag, last_modified,
-      received_bytes, total_bytes, state, danger_type, interrupt_reason,
-      opened);
+  CreateDownloadItemAdapter adapter(id, current_path, target_path, url_chain,
+                                    referrer_url, mime_type, original_mime_type,
+                                    start_time, end_time, etag, last_modified,
+                                    received_bytes, total_bytes, hash, state,
+                                    danger_type, interrupt_reason, opened);
   return MockCreateDownloadItem(adapter);
 }