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

components/update_client/utils.h

 // 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.
 
 #ifndef COMPONENTS_UPDATE_CLIENT_UTILS_H_
 #define COMPONENTS_UPDATE_CLIENT_UTILS_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 26 matching lines @@
 //        requestid="{7383396D-B4DD-46E1-9104-AAC6B918E792}"
 //        updaterchannel="canary" arch="x86" nacl_arch="x86-64"
 //        ADDITIONAL ATTRIBUTES>
 //   <hw physmemory="16"/>
 //   <os platform="win" version="6.1" arch="x86"/>
 //   ... REQUEST BODY ...
 // </request>
 
 // Builds a protocol request string by creating the outer envelope for
 // the request and including the request body specified as a parameter.
+// If present, the |download_preference| specifies a group policy that
+// affects the list of download URLs returned in the update response.
 // If specified, |additional_attributes| are appended as attributes of the
 // request element. The additional attributes have to be well-formed for
 // insertion in the request element.
 std::string BuildProtocolRequest(const std::string& browser_version,
                                  const std::string& channel,
                                  const std::string& lang,
                                  const std::string& os_long_name,
+                                 const std::string& download_preference,
                                  const std::string& request_body,
                                  const std::string& additional_attributes);
 
 // Sends a protocol request to the the service endpoint specified by |url|.
 // The body of the request is provided by |protocol_request| and it is
 // expected to contain XML data. The caller owns the returned object.
 scoped_ptr<net::URLFetcher> SendProtocolRequest(
     const GURL& url,
     const std::string& protocol_request,
     net::URLFetcherDelegate* url_fetcher_delegate,
@@ skipping 19 matching lines @@
 // Returns true if the file and the empty directory are deleted.
 bool DeleteFileAndEmptyParentDirectory(const base::FilePath& filepath);
 
 // Returns the component id of the |component|. The component id is in a
 // format similar with the format of an extension id.
 std::string GetCrxComponentID(const CrxComponent& component);
 
 }  // namespace update_client
 
 #endif  // COMPONENTS_UPDATE_CLIENT_UTILS_H_