[whatwg] Make the files attribute of the input element writable

[Cameron McCormack]

On 16/12/12 2:05 PM, Boris Zbarsky wrote:
> There's no way to express that in WebIDL, but I think that's a bug we
> should fix in WebIDL.  We should allow getters and setters for
> attributes to accept different IDL types...

Yeah, that has come up a couple of times now.  Filed 
https://www.w3.org/Bugs/Public/show_bug.cgi?id=20407.