Fix an issue that we didn't clean url request properly.

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 5a3af37402aec99f0743fa73cbc5b583f4a12cb0..dc189747f656debed42067704befb0cc7b9c3039 100644
--- a/content/browser/download/parallel_download_job.cc
+++ b/content/browser/download/parallel_download_job.cc
@@ -97,6 +97,15 @@ bool ParallelDownloadJob::UsesParallelRequests() const {
   return true;
 }
 
+void ParallelDownloadJob::CancelRequest(int64_t offset) {
+  if (initial_request_offset_ == offset)
+    DownloadJobImpl::Cancel(false);
+
+  auto it = workers_.find(offset);
+  if (it != workers_.end())
+    it->second->Cancel();
+}
+
 void ParallelDownloadJob::BuildParallelRequestAfterDelay() {
   DCHECK(workers_.empty());
   DCHECK(!requests_sent_);