Handle the case where IAttachmentExecute::Save() deletes a downloaded file.

content/browser/download/download_file_manager.h

 // Copyright (c) 2012 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
 // ResourceDispatcherHostImpl.
 //
 // The DownloadFileManager uses the file_thread for performing file write
@@ skipping 68 matching lines @@
  public:
   // Callback used with CreateDownloadFile().  |reason| will be
   // DOWNLOAD_INTERRUPT_REASON_NONE on a successful creation.
   typedef base::Callback<void(content::DownloadInterruptReason reason)>
       CreateDownloadFileCallback;
 
   // Callback used with RenameDownloadFile().
   typedef content::DownloadFile::RenameCompletionCallback
       RenameCompletionCallback;
 
+  // Callback used with CompleteDownload().
+  typedef content::DownloadFile::DetachCompletionCallback
+      CompleteCompletionCallback;
+
   // Takes ownership of the factory.
   // Passing in a NULL for |factory| will cause a default
   // |DownloadFileFactory| to be used.
   explicit DownloadFileManager(content::DownloadFileFactory* factory);
 
   // Create a download file and record it in the download file manager.
   virtual void CreateDownloadFile(
       scoped_ptr<DownloadCreateInfo> info,
       scoped_ptr<content::ByteStreamReader> stream,
       scoped_refptr<content::DownloadManager> download_manager,
       bool hash_needed,
       const net::BoundNetLog& bound_net_log,
       const CreateDownloadFileCallback& callback);
 
   // Called on shutdown on the UI thread.
   virtual void Shutdown();
 
   // Handlers for notifications sent from the UI thread and run on the
   // FILE thread.  These are both terminal actions with respect to the
   // download file, as far as the DownloadFileManager is concerned -- if
   // anything happens to the download file after they are called, it will
   // be ignored.
   // We call back to the UI thread in the case of CompleteDownload so that
   // we know when we can hand the file off to other consumers.
   virtual void CancelDownload(content::DownloadId id);
   virtual void CompleteDownload(content::DownloadId id,
-                                const base::Closure& callback);
+                                const CompleteCompletionCallback& callback);
 
   // Called on FILE thread by DownloadManager at the beginning of its shutdown.
   virtual void OnDownloadManagerShutdown(content::DownloadManager* manager);
 
   // Rename the download file, uniquifying if overwrite was not requested.
   virtual void RenameDownloadFile(
       content::DownloadId id,
       const FilePath& full_path,
       bool overwrite_existing_file,
       const RenameCompletionCallback& callback);
@@ skipping 35 matching lines @@
 
   // A map of all in progress downloads.  It owns the download files.
   DownloadFileMap downloads_;
 
   scoped_ptr<content::DownloadFileFactory> download_file_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileManager);
 };
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_