Use a custom URLRequestContextGetter for performing the secure proxy check.

chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_io_data.cc

 // Copyright 2015 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 "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_io_data.h"
 
 #include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h"
+#include "chrome/common/chrome_content_client.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/build_info.h"
 #endif
 
 #if defined(ENABLE_DATA_REDUCTION_PROXY_DEBUGGING)
 #include "chrome/browser/browser_process.h"
 #include "components/data_reduction_proxy/content/browser/content_data_reduction_proxy_debug_ui_service.h"
@@ skipping 27 matching lines @@
   if (DataReductionProxyParams::IsIncludedInAndroidOnePromoFieldTrial(
           base::android::BuildInfo::GetInstance()->android_build_fp())) {
     flags |= DataReductionProxyParams::kPromoAllowed;
   }
 #endif
 
   scoped_ptr<data_reduction_proxy::DataReductionProxyIOData>
       data_reduction_proxy_io_data(
           new data_reduction_proxy::DataReductionProxyIOData(
               DataReductionProxyChromeSettings::GetClient(), flags, net_log,
-              io_task_runner, ui_task_runner, enable_quic));
+              io_task_runner, ui_task_runner, enable_quic, GetUserAgent()));
   data_reduction_proxy_io_data->InitOnUIThread(prefs);
 
 #if defined(ENABLE_DATA_REDUCTION_PROXY_DEBUGGING)
   scoped_ptr<data_reduction_proxy::ContentDataReductionProxyDebugUIService>
       data_reduction_proxy_ui_service(
           new data_reduction_proxy::ContentDataReductionProxyDebugUIService(
               base::Bind(&data_reduction_proxy::DataReductionProxyConfigurator::
                              GetProxyConfig,
                          base::Unretained(
                              data_reduction_proxy_io_data->configurator())),
               ui_task_runner, io_task_runner,
               g_browser_process->GetApplicationLocale()));
   data_reduction_proxy_io_data->set_debug_ui_service(
       data_reduction_proxy_ui_service.Pass());
 #endif
 
   return data_reduction_proxy_io_data.Pass();
 }