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

content/browser/download/download_resource_handler.cc

 // Copyright (c) 2012 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 "content/browser/download/download_resource_handler.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 122 matching lines @@
 
   if (!response->headers ||
       !response->headers->EnumerateHeader(NULL,
                                           "Accept-Ranges",
                                           &accept_ranges_)) {
     accept_ranges_ = "";
   }
 
   info->prompt_user_for_save_location =
       save_info_.prompt_for_save_location && save_info_.file_path.empty();
-  info->referrer_charset = request_->context()->referrer_charset();
+  info->default_charset = request_->context()->default_charset();
   info->save_info = save_info_;
 
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&DownloadResourceHandler::StartOnUIThread, this,
                  base::Passed(&info), request_handle));
 
   // We can't start saving the data before we create the file on disk and have a
   // download id. The request will be un-paused in
@@ skipping 221 matching lines @@
                             " render_view_id_ = " "%d"
                             " save_info_.file_path = \"%" PRFilePath "\""
                             " }",
                             request_->url().spec().c_str(),
                             download_id_.local(),
                             global_id_.child_id,
                             global_id_.request_id,
                             render_view_id_,
                             save_info_.file_path.value().c_str());
 }