Polish the cleaning up url request code for parallel download.

content/browser/download/parallel_download_job.cc

Index: content/browser/download/parallel_download_job.cc
diff --git a/content/browser/download/parallel_download_job.cc b/content/browser/download/parallel_download_job.cc
index b6e5cae52fd879d226e9f364b090c8c2f2d94f26..fe1fc7c6cce6088737234f42dc3fa81e13997392 100644
--- a/content/browser/download/parallel_download_job.cc
+++ b/content/browser/download/parallel_download_job.cc
@@ -100,6 +100,7 @@ void ParallelDownloadJob::CancelRequestWithOffset(int64_t offset) {
   }
 
   auto it = workers_.find(offset);
+  DCHECK(it != workers_.end());
   if (it != workers_.end())

[qinmin, 2017/04/24 21:27:31]

nit: you can remove this if statement.

[xingliu, 2017/04/24 22:07:11]

Done.

     it->second->Cancel();
 }