Fix and refactor downloaded file handling in the loading stack

content/browser/loader/async_resource_handler.cc

 // Copyright (c) 2012 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/async_resource_handler.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/debug/alias.h"
 #include "base/feature_list.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/shared_memory.h"
 #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"
 #include "content/browser/loader/resource_message_filter.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/common/resource_messages.h"
 #include "content/common/resource_request_completion_status.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/resource_dispatcher_host_delegate.h"
 #include "content/public/common/content_features.h"
@@ skipping 316 matching lines @@
     rdh_->delegate()->OnResponseStarted(request(), info->GetContext(),
                                         response);
   }
 
   NetLogObserver::PopulateResponseInfo(request(), response);
   response->head.encoded_data_length = request()->raw_header_size();
 
   // 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();
   response->head.response_start = TimeTicks::Now();
   info->filter()->Send(new ResourceMsg_ReceivedResponse(GetRequestID(),
                                                         response->head));
   sent_received_response_msg_ = true;
 
   if (request()->response_info().metadata.get()) {
     std::vector<char> copy(request()->response_info().metadata->data(),
@@ skipping 217 matching lines @@
   } else {
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Net.ResourceLoader.ResponseStartToEnd.Over_512kB",
         elapsed_time, 1, 100000, 100);
   }
 
   inlining_helper_->RecordHistogram(elapsed_time);
 }
 
 }  // namespace content