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

components/update_client/utils.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/utils.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <cmath>
 
@@ skipping 46 matching lines @@
 
   return id;
 }
 
 }  // namespace
 
 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) {
   const std::string prod_id(
       UpdateQueryParams::GetProdIdString(UpdateQueryParams::CHROME));
 
   std::string request(
       "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
       "<request protocol=\"3.0\" ");
 
   if (!additional_attributes.empty())
@@ skipping 14 matching lines @@
       channel.c_str(),                    // "prodchannel"
       UpdateQueryParams::GetOS(),         // "os"
       UpdateQueryParams::GetArch(),       // "arch"
       UpdateQueryParams::GetNaclArch());  // "nacl_arch"
 #if defined(OS_WIN)
   const bool is_wow64(base::win::OSInfo::GetInstance()->wow64_status() ==
                       base::win::OSInfo::WOW64_ENABLED);
   if (is_wow64)
     base::StringAppendF(&request, " wow64=\"1\"");
 #endif
+  if (!download_preference.empty())
+    base::StringAppendF(&request, " dlpref=\"%s\"",
+                        download_preference.c_str());
   base::StringAppendF(&request, ">");
 
   // HW platform information.
   base::StringAppendF(&request, "<hw physmemory=\"%d\"/>",
                       GetPhysicalMemoryGB());  // "physmem" in GB.
 
   // OS version and platform information.
   base::StringAppendF(
       &request, "<os platform=\"%s\" version=\"%s\" arch=\"%s\"/>",
       os_long_name.c_str(),                                    // "platform"
@@ skipping 77 matching lines @@
 }
 
 std::string GetCrxComponentID(const CrxComponent& component) {
   const size_t kCrxIdSize = 16;
   CHECK_GE(component.pk_hash.size(), kCrxIdSize);
   return HexStringToID(base::ToLowerASCII(
       base::HexEncode(&component.pk_hash[0], kCrxIdSize)));
 }
 
 }  // namespace update_client