Add the background-fetch directory with an IDL Harness test (#5094)

This is based on the Background Fetch API that @jakearchibald has proposed in the WICG:
http://wicg.github.io/background-fetch/

The tests are ran both in a document and in a Service Worker.

View on GitHub: https://github.com/w3c/web-platform-tests/pull/5094

Received on Wednesday, 8 March 2017 17:44:15 UTC