Refactoring DownloadManager::DownloadURL to add proper annotation.

components/download/internal/test/test_download_driver.cc

Index: components/download/internal/test/test_download_driver.cc
diff --git a/components/download/internal/test/test_download_driver.cc b/components/download/internal/test/test_download_driver.cc
index 3f67629650da8c0b181b005376b469221aa51472..beffa6a69d443740ec83c369fb1846d12980e7f5 100644
--- a/components/download/internal/test/test_download_driver.cc
+++ b/components/download/internal/test/test_download_driver.cc
@@ -54,7 +54,9 @@ bool TestDownloadDriver::IsReady() const {
   return is_ready_;
 }
 
-void TestDownloadDriver::Start(const DownloadParams& params) {
+void TestDownloadDriver::Start(
+    const DownloadParams& params,
+    const net::NetworkTrafficAnnotationTag& traffic_annotation) {
   DriverEntry entry;
   entry.guid = params.guid;
   entry.state = DriverEntry::State::IN_PROGRESS;