Implement Windows GPO support for "dlpref" in component updater.

components/update_client/update_checker.cc

 // Copyright 2014 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 "components/update_client/update_checker.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
@@ skipping 51 matching lines @@
                           "<packages>"
                           "<package fp=\"%s\"/>"
                           "</packages>",
                           item->component.fingerprint.c_str());
     }
     base::StringAppendF(&app, "</app>");
     app_elements.append(app);
     VLOG(1) << "Appending to update request: " << app;
   }
 
-  return BuildProtocolRequest(config.GetBrowserVersion().GetString(),
-                              config.GetChannel(), config.GetLang(),
-                              config.GetOSLongName(), app_elements,
-                              additional_attributes);
+  return BuildProtocolRequest(
+      config.GetBrowserVersion().GetString(), config.GetChannel(),
+      config.GetLang(), config.GetOSLongName(), config.GetDownloadPreference(),
+      app_elements, additional_attributes);
 }
 
 class UpdateCheckerImpl : public UpdateChecker {
  public:
   explicit UpdateCheckerImpl(const scoped_refptr<Configurator>& config);
   ~UpdateCheckerImpl() override;
 
   // Overrides for UpdateChecker.
   bool CheckForUpdates(
       const std::vector<CrxUpdateItem*>& items_to_check,
@@ skipping 80 matching lines @@
 }
 
 }  // namespace
 
 scoped_ptr<UpdateChecker> UpdateChecker::Create(
     const scoped_refptr<Configurator>& config) {
   return scoped_ptr<UpdateChecker>(new UpdateCheckerImpl(config));
 }
 
 }  // namespace update_client