Fix and refactor downloaded file handling in the loading stack

content/browser/loader/mojo_async_resource_handler.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/loader/mojo_async_resource_handler.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/logging.h"
 #include "base/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_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/common/resource_request_completion_status.h"
 #include "content/public/browser/resource_dispatcher_host_delegate.h"
 #include "content/public/common/resource_response.h"
 #include "mojo/public/c/system/data_pipe.h"
 #include "mojo/public/cpp/system/data_pipe.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
@@ skipping 108 matching lines @@
   if (rdh_->delegate()) {
     rdh_->delegate()->OnResponseStarted(request(), info->GetContext(),
                                         response);
   }
 
   NetLogObserver::PopulateResponseInfo(request(), response);
 
   response->head.request_start = request()->creation_time();
   response->head.response_start = base::TimeTicks::Now();
   sent_received_response_message_ = true;
-  url_loader_client_->OnReceiveResponse(response->head);
+
+  mojom::DownloadedTempFilePtr downloaded_file_ptr;
+  if (!response->head.download_file_path.empty()) {
+    auto downloaded_file = base::MakeUnique<DownloadedTempFileImpl>(
+        rdh_, info->GetChildID(), info->GetRequestID(),
+        response->head.download_file_path);
+    downloaded_file_ptr = downloaded_file->CreateInterfacePtrAndBind();
+    rdh_->RegisterDownloadedTempFile(std::move(downloaded_file));
+  }
+
+  url_loader_client_->OnReceiveResponse(response->head,
+                                        std::move(downloaded_file_ptr));
   return true;
 }
 
 bool MojoAsyncResourceHandler::OnWillStart(const GURL& url, bool* defer) {
   return true;
 }
 
 bool MojoAsyncResourceHandler::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
                                           int* buf_size,
                                           int min_size) {
@@ skipping 240 matching lines @@
 
   controller()->CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);
   return false;
 }
 
 void MojoAsyncResourceHandler::OnWritable(MojoResult unused) {
   Resume();
 }
 
 }  // namespace content