> I agree about not using html.FileEntry as they are not compatible (sadly) 

It was a bit of an aha moment when I found out that they weren't compatible.

> why don't you use chrome.FileEntry in the public API instead of js.Proxy

I guess my idea is that we try and faithfully map to the chrome APIs, w/o doing too much magic. Then there might be some convenience layer sitting on top which uses those APIs but improves on their usability. In an ideal world, the faithful mapping is auto-generated, and the high-level convenience layer is hand-coded.

> in your example the first line of the user continuation is always:

I agree, that will most likely be the case. I'm not 100% for returning js.Proxy; I can change this to chrome.FileEntry if it makes sense.