referrer_charset is a lie. It's really the user's default_charset.

net/url_request/url_request_context.cc

 // Copyright (c) 2011 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 "net/url_request/url_request_context.h"
 
 #include "base/compiler_specific.h"
 #include "base/string_util.h"
 #include "net/base/cookie_store.h"
 #include "net/base/host_resolver.h"
@@ skipping 30 matching lines @@
   set_http_auth_handler_factory(other->http_auth_handler_factory());
   set_proxy_service(other->proxy_service());
   set_ssl_config_service(other->ssl_config_service());
   set_network_delegate(other->network_delegate());
   set_http_server_properties(other->http_server_properties());
   set_cookie_store(other->cookie_store());
   set_transport_security_state(other->transport_security_state());
   // FTPAuthCache is unique per context.
   set_accept_language(other->accept_language());
   set_accept_charset(other->accept_charset());
-  set_referrer_charset(other->referrer_charset());
+  set_default_charset(other->default_charset());
   set_http_transaction_factory(other->http_transaction_factory());
   set_ftp_transaction_factory(other->ftp_transaction_factory());
   set_job_factory(other->job_factory());
 }
 
 void URLRequestContext::set_cookie_store(CookieStore* cookie_store) {
   cookie_store_ = cookie_store;
 }
 
 const std::string& URLRequestContext::GetUserAgent(const GURL& url) const {
   return EmptyString();
 }
 
 URLRequestContext::~URLRequestContext() {
 }
 
 }  // namespace net