Added DownloadProcessHandle class.

chrome/browser/download/download_file_manager.h

 // 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.
 //
 // 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.
 //
 // The DownloadFileManager uses the file_thread for performing file write
@@ skipping 29 matching lines @@
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_
 #pragma once
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/timer.h"
+#include "chrome/browser/download/download_process_handle.h"
 #include "ui/gfx/native_widget_types.h"
 
 struct DownloadBuffer;
 struct DownloadCreateInfo;
 struct DownloadSaveInfo;
 class DownloadFile;
 class DownloadManager;
 class FilePath;
 class GURL;
 class ResourceDispatcherHost;
@@ skipping 76 matching lines @@
   void OnShutdown();
 
   // Creates DownloadFile on FILE thread and continues starting the download
   // process.
   void CreateDownloadFile(DownloadCreateInfo* info,
                           DownloadManager* download_manager,
                           bool hash_needed);
 
   // Tells the ResourceDispatcherHost to resume a download request
   // that was paused to wait for the on-disk file to be created.
-  void ResumeDownloadRequest(int child_id, int request_id);
+  void ResumeDownloadRequest(DownloadProcessHandle process);

[Paweł Hajdan Jr., 2011/05/09 19:47:31]

nit: Why not a pointer?

[ahendrickson, 2011/05/10 18:04:43]

Because it's called from other threads, and this way we don't have to worry
about object lifetimes.

[Paweł Hajdan Jr., 2011/05/10 18:58:04]

I see, makes sense. Could you add a short comment in each place which does the
copy?

 
   // Called only on the download thread.
   DownloadFile* GetDownloadFile(int id);
 
   // Called only from RenameInProgressDownloadFile and
   // RenameCompletingDownloadFile on the FILE thread.
   void CancelDownloadOnRename(int id);
 
   // Erases the download file with the given the download |id| and removes
   // it from the maps.
@@ skipping 10 matching lines @@
   // Schedule periodic updates of the download progress. This timer
   // is controlled from the FILE thread, and posts updates to the UI thread.
   base::RepeatingTimer<DownloadFileManager> update_timer_;
 
   ResourceDispatcherHost* resource_dispatcher_host_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileManager);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_