Added DownloadProcessHandle class.

chrome/browser/download/download_util.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.
 //
 // Download utilities.
 
 #ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_UTIL_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_UTIL_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/string16.h"
+#include "chrome/browser/download/download_process_handle.h"
 #include "ui/gfx/native_widget_types.h"
 
 #if defined(TOOLKIT_VIEWS)
 #include "views/view.h"
 #endif
 
 namespace gfx {
 class Canvas;
 class Image;
 }
@@ skipping 209 matching lines @@
                  const GURL& referrer,
                  const std::string& referrer_charset,
                  const DownloadSaveInfo& save_info,
                  ResourceDispatcherHost* rdh,
                  int render_process_host_id,
                  int render_view_id,
                  net::URLRequestContextGetter* request_context_getter);
 
 // Tells the resource dispatcher host to cancel a download request.
 // Must be called on the IO thread.
+// |process_handle| is passed by value because it is ultimately passed to
+// other threads, and this way we don't have to worry about object lifetimes.
 void CancelDownloadRequest(ResourceDispatcherHost* rdh,
-                           int render_process_id,
-                           int request_id);
+                           DownloadProcessHandle process_handle);
 
 // Sends a notification on downloads being initiated
 // Must be called on the UI thread.
 void NotifyDownloadInitiated(int render_process_id, int render_view_id);
 
 // Same as GetUniquePathNumber, except that it also checks the existence
 // of its .crdownload intermediate path.
 // If |path| does not exist, 0 is returned.  If it fails to find such
 // a number, -1 is returned.
 int GetUniquePathNumberWithCrDownload(const FilePath& path);
 
 // Erases all downloaded files with the specified path and name prefix.
 // Used by download UI tests to clean up the download directory.
 void EraseUniqueDownloadFiles(const FilePath& path_prefix);
 
 // Returns a .crdownload intermediate path for the |suggested_path|.
 FilePath GetCrDownloadPath(const FilePath& suggested_path);
 
 // Returns true if this download should show the "dangerous file" warning.
 // Various factors are considered, such as the type of the file, whether a
 // user action initiated the download, and whether the user has explictly
 // marked the file type as "auto open".
 bool IsDangerous(DownloadCreateInfo* info, Profile* profile, bool auto_open);
 
 }  // namespace download_util
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_UTIL_H_