[whatwg] SQL API and changeVersion() with no callbacks

[Brady Eidson]

One of the changeVersion variants is -

void changeVersion(in DOMString oldVersion, in DOMString newVersion);

This allows an asynchronous version change with no way at all to  
determine success or failure of the operation.

I'm just curious what the motivation is.  Is it necessary to support  
this?

Thanks,
~Brady