Fix and refactor downloaded file handling in the loading stack

content/browser/loader/async_resource_handler.cc

Index: content/browser/loader/async_resource_handler.cc
diff --git a/content/browser/loader/async_resource_handler.cc b/content/browser/loader/async_resource_handler.cc
index 2c5badcd5e11c2ca7f1a71ae40b66e60ddf8f82b..8f32a9fbcfcd4d537a2e38c1e2bf52da53b9a12d 100644
--- a/content/browser/loader/async_resource_handler.cc
+++ b/content/browser/loader/async_resource_handler.cc
@@ -17,6 +17,7 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
+#include "content/browser/loader/downloaded_temp_file_impl.h"
 #include "content/browser/loader/netlog_observer.h"
 #include "content/browser/loader/resource_buffer.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
@@ -353,9 +354,10 @@ bool AsyncResourceHandler::OnResponseStarted(ResourceResponse* 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(),
+    auto downloaded_file = base::MakeUnique<DownloadedTempFileImpl>(
+        rdh_, info->GetChildID(), info->GetRequestID(),
         response->head.download_file_path);
+    rdh_->RegisterDownloadedTempFile(std::move(downloaded_file));
   }
 
   response->head.request_start = request()->creation_time();