Re: Fetch API

http://fetch.spec.whatwg.org/#dom-request
Add steps to set client and context?

http://fetch.spec.whatwg.org/#cors-preflight-fetch-0
Add steps to set client and context?

http://fetch.spec.whatwg.org/#concept-legacy-fetch
http://fetch.spec.whatwg.org/#concept-legacy-potentially-cors-enabled-fetch
Steps to set url, client and context are missing here too. But not worth
updating this section anymore?

Termination reason is not handled intentionally (only supposed to be used
by XHR's functionalities and nothing would be introduced for Fetch API?)?

The promise is rejected with a TypeError which seems inconsistent with XHR.
Is this intentional?