Change URLRequest to use a ref-counted buffer for actual IO....

chrome/browser/download/download_file.h

 // Copyright (c) 2006-2008 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.
 //
 // Objects that handle file operations for downloads, on the download thread.
 //
 // The DownloadFileManager owns a set of DownloadFile objects, each of which
 // represent one in progress download and performs the disk IO for that
 // download. The DownloadFileManager itself is a singleton object owned by the
 // ResourceDispatcherHost.
@@ skipping 34 matching lines @@
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
 #include "base/lock.h"
 #include "base/ref_counted.h"
 #include "base/thread.h"
 #include "base/timer.h"
 #include "chrome/browser/history/download_types.h"
 
+namespace net {
+class IOBuffer;
+}
 class DownloadManager;
 class FilePath;
 class GURL;
 class MessageLoop;
 class ResourceDispatcherHost;
 class URLRequestContext;
 
 // DownloadBuffer --------------------------------------------------------------
 
 // This container is created and populated on the io_thread, and passed to the
 // file_thread for writing. In order to avoid flooding the file_thread with too
 // many small write messages, each write is appended to the DownloadBuffer while
 // waiting for the task to run on the file_thread. Access to the write buffers
 // is synchronized via the lock. Each entry in 'contents' represents one data
 // buffer and its size in bytes.
 
 struct DownloadBuffer {
   Lock lock;
-  typedef std::pair<char *, int> Contents;
+  typedef std::pair<net::IOBuffer*, int> Contents;
   std::vector<Contents> contents;
 };
 
 // DownloadFile ----------------------------------------------------------------
 
 // These objects live exclusively on the download thread and handle the writing
 // operations for one download. These objects live only for the duration that
 // the download is 'in progress': once the download has been completed or
 // cancelled, the DownloadFile is destroyed.
 class DownloadFile {
@@ skipping 180 matching lines @@
   // Used for progress updates on the UI thread, mapping download->id() to bytes
   // received so far. Written to by the file thread and read by the UI thread.
   typedef base::hash_map<int, int64> ProgressMap;
   ProgressMap ui_progress_;
   Lock progress_lock_;
 
   DISALLOW_EVIL_CONSTRUCTORS(DownloadFileManager);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H__