The files in this directory came from downloading a test extension from the
webstore* that had properly signed verified_contents.json file, taking all
extension files (including _metadata/verified_contents.json and
_metadata/computed_hashes.json) from the .crx and putting them into
source.zip file. The files in the source directory are only for reference and
not used in tests.

The background script is accidently listed as an icon, and has become corrupted.

* https://chrome.google.com/webstore/detail/gpcgjpkhcgbdncmcaddhlhpccfckdoip