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

content/browser/download/download_item_impl.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 "content/browser/download/download_item_impl.h"
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 194 matching lines @@
                   info.prompt_user_for_save_location),
       request_handle_(request_handle),
       download_id_(info.download_id),
       full_path_(info.path),
       url_chain_(info.url_chain),
       referrer_url_(info.referrer_url),
       suggested_filename_(UTF16ToUTF8(info.save_info.suggested_name)),
       content_disposition_(info.content_disposition),
       mime_type_(info.mime_type),
       original_mime_type_(info.original_mime_type),
-      referrer_charset_(info.referrer_charset),
+      default_charset_(info.default_charset),
       remote_address_(info.remote_address),
       total_bytes_(info.total_bytes),
       received_bytes_(0),
       bytes_per_sec_(0),
       last_reason_(DOWNLOAD_INTERRUPT_REASON_NONE),
       start_tick_(base::TimeTicks::Now()),
       state_(IN_PROGRESS),
       start_time_(info.start_time),
       db_handle_(DownloadItem::kUninitializedHandle),
       delegate_(delegate),
@@ skipping 696 matching lines @@
 std::string DownloadItemImpl::GetSuggestedFilename() const {
   return suggested_filename_;
 }
 std::string DownloadItemImpl::GetContentDisposition() const {
   return content_disposition_;
 }
 std::string DownloadItemImpl::GetMimeType() const { return mime_type_; }
 std::string DownloadItemImpl::GetOriginalMimeType() const {
   return original_mime_type_;
 }
-std::string DownloadItemImpl::GetReferrerCharset() const {
-  return referrer_charset_;
+std::string DownloadItemImpl::GetDefaultCharset() const {
+  return default_charset_;
 }
 std::string DownloadItemImpl::GetRemoteAddress() const {
   return remote_address_;
 }
 int64 DownloadItemImpl::GetTotalBytes() const { return total_bytes_; }
 void DownloadItemImpl::SetTotalBytes(int64 total_bytes) {
   total_bytes_ = total_bytes;
 }
 const std::string& DownloadItemImpl::GetHash() const { return hash_; }
 int64 DownloadItemImpl::GetReceivedBytes() const { return received_bytes_; }
@@ skipping 58 matching lines @@
   std::map<const void*, ExternalData*>::iterator it =
       external_data_map_.find(key);
 
   if (it == external_data_map_.end()) {
     external_data_map_[key] = data;
   } else if (it->second != data) {
     delete it->second;
     it->second = data;
   }
 }