Trying to download a file from an extension page fails for both data-URIs as well as blobs.
See demo extension:
http://jeurissen.co/webext-demos/download-file-links-and-blob
These should work just fine. Extensions should be able to download files without requiring the downloads permission/API.
Version 1.1.1 (149), WebKit 625.1.8
Tahoe (26)
