Refactoring DownloadManager::DownloadURL to add proper annotation.

content/browser/download/download_worker.cc

Index: content/browser/download/download_worker.cc
diff --git a/content/browser/download/download_worker.cc b/content/browser/download/download_worker.cc
index 5eff1cf3b38a134ff8f12c54e3f57b06a360abc6..c1fea1839ac623a788b70b1d1afae80248e8ffbf 100644
--- a/content/browser/download/download_worker.cc
+++ b/content/browser/download/download_worker.cc
@@ -7,6 +7,7 @@
 #include "content/browser/download/download_create_info.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/web_contents.h"
+#include "net/traffic_annotation/network_traffic_annotation.h"
 
 namespace content {
 namespace {
@@ -38,8 +39,8 @@ CreateUrlDownloader(std::unique_ptr<DownloadUrlParameters> params,
   // Build the URLRequest, BlobDataHandle is hold in original request for image
   // download.
   std::unique_ptr<net::URLRequest> url_request =
-      DownloadRequestCore::CreateRequestOnIOThread(DownloadItem::kInvalidId,
-                                                   params.get());
+      DownloadRequestCore::CreateRequestOnIOThread(
+          DownloadItem::kInvalidId, params.get(), NO_TRAFFIC_ANNOTATION_YET);
 
   return std::unique_ptr<UrlDownloader, BrowserThread::DeleteOnIOThread>(
       UrlDownloader::BeginDownload(delegate, std::move(url_request),