kiyoshi, any method to wrap a HTML5 app in an EXE is likely to add a lot to the filesize, since it basically has to contain an entire browser.
I fear this thread is going in circles - I've written a lot of discussion already on this thread so I'm not going to say any more, just that you should make sure you've read the entire thread.
I've also always encouraged people to use EXE wrappers themselves, since it ought to be straightforward. As I said before other than Steam I can't see the point, but if you want to you can. I did also try contacting Awesomium myself in case it was straightforward to make an official wrapper, but they don't seem to have got back to me which is disappointing. So let me know if any of the other wrappers work well for you!