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

content/browser/download/download_file_manager.h

Index: content/browser/download/download_file_manager.h
diff --git a/content/browser/download/download_file_manager.h b/content/browser/download/download_file_manager.h
index c86ca2a2962f43a87595a1dab48309a43246f072..cc5fa89db42ceb244baa39cd13935bf16030bfcb 100644
--- a/content/browser/download/download_file_manager.h
+++ b/content/browser/download/download_file_manager.h
@@ -86,6 +86,10 @@ class CONTENT_EXPORT DownloadFileManager
   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.
@@ -112,7 +116,7 @@ class CONTENT_EXPORT DownloadFileManager
   // 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);