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

net/base/net_log_event_type_list.h

Index: net/base/net_log_event_type_list.h
diff --git a/net/base/net_log_event_type_list.h b/net/base/net_log_event_type_list.h
index 4003d9bbccb882aacddc67007f47d1d6413e03ff..d1a4e1f636f4aab0cc7971e96f43231655dfc474 100644
--- a/net/base/net_log_event_type_list.h
+++ b/net/base/net_log_event_type_list.h
@@ -1579,7 +1579,7 @@ EVENT_TYPE(DOWNLOAD_ITEM_RENAMED)
 
 // This event is created when a download item is interrupted.
 //   {
-//     "reason": <The reason for the interruption>,
+//     "interrupt_reason": <The reason for the interruption>,
 //     "bytes_so_far": <Number of bytes received>,
 //     "hash_state": <Current hash state, as a hex-encoded binary string>,
 //   }
@@ -1656,6 +1656,8 @@ EVENT_TYPE(DOWNLOAD_FILE_DELETED)
 //   {
 //     "operation": <open, write, close, etc>,
 //     "net_error": <net::Error code>,
+//     "os_error": <OS depedent error code>
+//     "interrupt_reason": <Download interrupt reason>
 //   }
 EVENT_TYPE(DOWNLOAD_FILE_ERROR)