Remove the dependence on BrowserThread::FILE for

chrome/service/net/service_url_request_context_getter.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 "chrome/service/net/service_url_request_context_getter.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/compiler_specific.h"
@@ skipping 84 matching lines @@
   return user_agent;
 }
 
 }  // namespace
 
 ServiceURLRequestContextGetter::ServiceURLRequestContextGetter()
     : user_agent_(MakeUserAgentForServiceProcess()),
       network_task_runner_(g_service_process->io_task_runner()) {
   DCHECK(g_service_process);
   proxy_config_service_ = net::ProxyService::CreateSystemProxyConfigService(
-      g_service_process->io_task_runner(),
-      g_service_process->file_task_runner());
+      g_service_process->io_task_runner());
 }
 
 net::URLRequestContext*
 ServiceURLRequestContextGetter::GetURLRequestContext() {
   if (!url_request_context_.get()) {
     net::URLRequestContextBuilder builder;
     builder.set_user_agent(user_agent_);
     builder.set_accept_language("en-us,fr");
     builder.set_proxy_config_service(std::move(proxy_config_service_));
     builder.set_throttling_enabled(true);
     url_request_context_ = builder.Build();
   }
   return url_request_context_.get();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 ServiceURLRequestContextGetter::GetNetworkTaskRunner() const {
   return network_task_runner_;
 }
 
 ServiceURLRequestContextGetter::~ServiceURLRequestContextGetter() {}