The PR was merged.

Again, I don't have much strong preference on the naming as long as it could indicate what you want to express.

Whether to prefix is* to a boolean flag or not is more or less a kind of the editor preference. DOM API's may not use is*, but some other specs prefer to use is*, see [1] for file entry definition. It use `isFile` and `isDirectory` to indicate the type of a file entry.

[1] http://www.w3.org/TR/file-system-api/#idl-def-Entry