Fix various issues in RedirectToFileResourceHandler.

content/browser/loader/sync_resource_handler.cc

Index: content/browser/loader/sync_resource_handler.cc
diff --git a/content/browser/loader/sync_resource_handler.cc b/content/browser/loader/sync_resource_handler.cc
index 1310d0f36691e2d383e292d3ac08f7c114017b4c..8a830951aa3cedf1fbd1339c456acbb3b06cae3b 100644
--- a/content/browser/loader/sync_resource_handler.cc
+++ b/content/browser/loader/sync_resource_handler.cc
@@ -83,6 +83,14 @@ bool SyncResourceHandler::OnResponseStarted(
 
   DevToolsNetLogObserver::PopulateResponseInfo(request(), response);
 
+  // If the parent handler downloaded the resource to a file, grant the child
+  // read permissions on it.
+  if (!response->head.download_file_path.empty()) {
+    rdh_->RegisterDownloadedTempFile(
+        info->GetChildID(), info->GetRequestID(),
+        response->head.download_file_path);
+  }
+
   // We don't care about copying the status here.
   result_.headers = response->head.headers;
   result_.mime_type = response->head.mime_type;