shirosaki/GMail-Conversation-View — comment on commit 99f44bd53438599198079dcd70c6d9b4c1957d53
File:  line 0
By shirosaki:

I confirmed that by adding Log output.
HTMLDocument and Window don't have classList.

```javascript
Log.error("target: " + event.target);
Log.error("classList: " + event.target.classList);
```

2011-11-04 11:33:06	Conversations.Modules.Enigmail	ERROR	target: [object HTMLLIElement]
2011-11-04 11:33:06	Conversations.Modules.Enigmail	ERROR	classList: message signed collapsed

2011-11-04 11:33:08	Conversations.Modules.Enigmail	ERROR	target: [object HTMLDocument]
2011-11-04 11:33:08	Conversations.Modules.Enigmail	ERROR	classList: undefined

2011-11-04 11:33:08	Conversations.Modules.Enigmail	ERROR	target: [object Window]
2011-11-04 11:33:08	Conversations.Modules.Enigmail	ERROR	classList: undefined

2011-11-04 11:40:25	Conversations.Modules.Enigmail	ERROR	target: javascript:
2011-11-04 11:40:25	Conversations.Modules.Enigmail	ERROR	classList: link