Move the download code to new directories:

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 20 matching lines @@
 //                                                    io_thread (stops net IO
 //                                                               for download)
 //
 // The DownloadFileManager tracks download requests, mapping from a download
 // ID (unique integer created in the IO thread) to the DownloadManager for the
 // tab (profile) where the download was initiated. In the event of a tab closure
 // during a download, the DownloadFileManager will continue to route data to the
 // appropriate DownloadManager. In progress downloads are cancelled for a
 // DownloadManager that exits (such as when closing a profile).
 
-#ifndef CHROME_BROWSER_DOWNLOAD_FILE_H__
-#define CHROME_BROWSER_DOWNLOAD_FILE_H__
+#ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H__
+#define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H__
 
 #include <string>
 #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"
@@ skipping 210 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_FILE_H__
+#endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H__