Add a delay to send the parallel requests.

content/browser/download/parallel_download_job.h

 // Copyright 2017 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.
 
 #ifndef CONTENT_BROWSER_DOWNLOAD_PARALLEL_DOWNLOAD_JOB_H_
 #define CONTENT_BROWSER_DOWNLOAD_PARALLEL_DOWNLOAD_JOB_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/timer/timer.h"
 #include "content/browser/download/download_job_impl.h"
 #include "content/browser/download/download_worker.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
 // DownloadJob that can create concurrent range requests to fetch different
 // parts of the file.
 // The original request is hold in base class DownloadUrlJob.
 class CONTENT_EXPORT ParallelDownloadJob : public DownloadJobImpl {
@@ skipping 31 matching lines @@
   // Create one range request, virtual for testing.
   virtual void CreateRequest(int64_t offset, int64_t length);
 
   // Information about the initial request when download is started.
   int64_t initial_request_offset_;
   int64_t initial_request_length_;
 
   // Subsequent tasks to send range requests.
   WorkerList workers_;
 
+  // Used to send parallel requests after a delay based on Finch config.
+  std::unique_ptr<base::OneShotTimer> timer_;

[qinmin, 2017/03/15 05:49:18]

You don't need the unique_ptr, just use base::OneShotTimer timer_.

[xingliu, 2017/03/15 17:48:52]

Done, make sense.

+
   DISALLOW_COPY_AND_ASSIGN(ParallelDownloadJob);
 };
 
 }  //  namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_PARALLEL_DOWNLOAD_JOB_H_