[Downloads] Move client guid for AV scanning of downloaded files to chrome/

content/public/browser/download_manager_delegate.cc

 // Copyright (c) 2012 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.
 
 #include "content/public/browser/download_manager_delegate.h"
 
 #include "content/public/browser/download_item.h"
 
 namespace content {
 
@@ skipping 20 matching lines @@
 
 bool DownloadManagerDelegate::ShouldOpenDownload(
     DownloadItem* item, const DownloadOpenDelayedCallback& callback) {
   return true;
 }
 
 bool DownloadManagerDelegate::GenerateFileHash() {
   return false;
 }
 
+std::string
+DownloadManagerDelegate::ApplicationClientIdForFileScanning() const {
+  return std::string();
+}
+
 DownloadManagerDelegate::~DownloadManagerDelegate() {}
 
 }  // namespace content