Refactoring DownloadManager::DownloadURL to add proper annotation.

components/download/internal/download_driver.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 COMPONENTS_DOWNLOAD_INTERNAL_DOWNLOAD_DRIVER_H_
 #define COMPONENTS_DOWNLOAD_INTERNAL_DOWNLOAD_DRIVER_H_
 
 #include <string>
 
 #include "base/optional.h"
 #include "components/download/internal/driver_entry.h"
+#include "net/traffic_annotation/network_traffic_annotation.h"
 
 namespace base {
 class FilePath;
 }  // namespace base
 
 namespace download {
 
 struct DownloadParams;
 
 // The interface that includes all the operations to interact with low level
@@ skipping 26 matching lines @@
 
   // Initialize the driver to receive download updates.
   virtual void Initialize(Client* client) = 0;
 
   // Returns if the driver is ready. Returns false when the driver is not
   // initialized by the client, or low level download library has been shut
   // down.
   virtual bool IsReady() const = 0;
 
   // Starts a new download.
-  virtual void Start(const DownloadParams& params) = 0;
+  virtual void Start(
+      const DownloadParams& params,
+      const net::NetworkTrafficAnnotationTag& traffic_annotation) = 0;
 
   // Cancels an existing download, all data associated with this download should
   // be removed.
   virtual void Cancel(const std::string& guid) = 0;
 
   // Pauses the download.
   virtual void Pause(const std::string& guid) = 0;
 
   // Resumes the download
   virtual void Resume(const std::string& guid) = 0;
 
   // Find a download record from low level download library.
   virtual base::Optional<DriverEntry> Find(const std::string& guid) = 0;
 };
 
 }  // namespace download
 
 #endif  // COMPONENTS_DOWNLOAD_INTERNAL_DOWNLOAD_DRIVER_H_