Added net logging to DownloadItem.

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 c4d188e3c7441e6b58c259b7be174ebd9bfbaff2..06ce4f0ab7c6f3ede94b6bf7b7d2b8426e75b43d 100644
--- a/net/base/net_log_event_type_list.h
+++ b/net/base/net_log_event_type_list.h
@@ -1449,6 +1449,103 @@ EVENT_TYPE(HTTP_PIPELINED_CONNECTION_RECEIVED_HEADERS)
 EVENT_TYPE(HTTP_PIPELINED_CONNECTION_STREAM_CLOSED)
 
 // ------------------------------------------------------------------------
+// Download start events.
+// ------------------------------------------------------------------------
+
+// This event is created when a download is started, and lets the URL request
+// event source know what download source it is using.
+//   {
+//     "source_dependency": <Source id of the download>,
+//   }
+EVENT_TYPE(DOWNLOAD_STARTED)
+
+// This event is created when a download is started, and lets the download
+// event source know what URL request it's associated with.
+//   {
+//     "source_dependency": <Source id of the request being waited on>,
+//   }
+EVENT_TYPE(DOWNLOAD_URL_REQUEST)
+
+// ------------------------------------------------------------------------
+// DownloadItem events.
+// ------------------------------------------------------------------------
+
+// This event lives for as long as a download item is active.
+// The BEGIN event occurs right after constrction, and has the following
+// parameters:
+//   {
+//     "type": <New/history/save page>,
+//     "id": <Download ID>,
+//     "original_url": <URL that initiated the download>,
+//     "final_url": <URL of the actual download file>,
+//     "file_name": <file name>,

[Randy Smith (Not in Mondays), 2012/02/06 22:34:59]

If you're willing, I'd like a *little* bit more information here.  I think most
of the time this will be null for regular downloads; is that correct?  Under
what cases will it not be correct?

[ahendrickson, 2012/02/07 00:16:19]

I talked to Asanka.

For History downloads, we will use full_path_.

For regular and Save As downloads, it will use one of (in order of preference):

1. state_info_.force_filename
2. suggested_filename_
3. The file name at the end of the final URL.

See DownloadItemImpl::Init().

In any case, the file name can change.

[Randy Smith (Not in Mondays), 2012/02/07 15:09:45]

I don't think we communicated (though I suppose "expected" counts as a *little*
bit more information :-}).  My goal is for someone who doesn't know the download
system to be able to look at this documentation and understand what "file name"
means.  Do you feel like that's the case?  I don't feel like I know, and I *do*
know the download system.  History download->real filename.  Regular download? 
Save Page As?

[ahendrickson, 2012/02/07 17:18:35]

Put more detail into the comment.

+//     "safety_state": <SAFE, DANGEROUS, DANGEROUS_BUT_VALIDATED>,
+//     "start_offset": <Where to start writing (defaults to 0)>,
+//   }
+// The END event will occur when the download is interrupted, canceled or
+// completed.
+EVENT_TYPE(DOWNLOAD_ITEM_ACTIVE)
+
+// This event is created when a download item has been checked by the
+// safe browsing system.
+//   {
+//     "safety_state": <SAFE, DANGEROUS, DANGEROUS_BUT_VALIDATED>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_SAFETY_STATE_UPDATED)
+
+// This event is created when a download item has been inserted into the
+// history database.
+//   {
+//     "db_handle": <The database handle for the item>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_IN_HISTORY)
+
+// This event is created when a download item is updated.
+//   {
+//     "bytes_so_far": <Number of bytes received>,
+//     "hash_state": <Current hash state, as a hex-encoded binary string>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_UPDATED)
+
+// This event is created when a download item is renamed.
+//   {
+//     "old_filename": <Old file name>,
+//     "new_filename": <New file name>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_RENAMED)
+
+// This event is created when a download item is interrupted.
+//   {
+//     "reason": <The reason for the interruption>,
+//     "bytes_so_far": <Number of bytes received>,
+//     "hash_state": <Current hash state, as a hex-encoded binary string>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_INTERRUPTED)
+
+// This event is created when a download item is resumed.
+//   {
+//     "user_initiated": <True if user initiated resume>,
+//     "reason": <The reason for the interruption>,
+//     "bytes_so_far": <Number of bytes received>,
+//     "hash_state": <Current hash state, as a hex-encoded binary string>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_RESUMED)
+
+// This event is created when a download item is finished.
+//   {
+//     "bytes_so_far": <Number of bytes received>,
+//     "final_hash": <Final hash, as a hex-encoded binary string>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_FINISHED)
+
+// This event is created when a download item is canceled.
+//   {
+//     "bytes_so_far": <Number of bytes received>,
+//     "hash_state": <Current hash state, as a hex-encoded binary string>,
+//   }
+EVENT_TYPE(DOWNLOAD_ITEM_CANCELED)
+
+// ------------------------------------------------------------------------
 // DownloadFile events.
 // ------------------------------------------------------------------------