This change removes gr-gapi-auth and merge gr-gerrit-auth into one
gr-auth static API, exposed as Gerrit.Auth to enable cross-domain
configuration for embedded scenario.
Apparently, Google Platform JS library shares state across instances,
and as a result for embedded use case PolyGerrit requesting OAuth
sequence breaks other instances. To mitigate that, this change provides
an interface similar to Gerrit.Nav for setting OAuth access tokens.
``` js
Gerrit.Auth.setup(getToken, defaultOptions)
```
Gerrit.Auth.setup takes following parameters:
- getToken takes a function that returns Promise resolving to full token
object (including `access_token` and `expires_at` properties)
- defaultOptions may contain `credentials` fetch option that will be
used for all HTTP requests if provided
With the access_token PolyGerrit uses Gerrit's "faster CORS":
- REST API endpoints are prefixed with /a/ (after base url)
- access_token is added as URL param
- all but GET requests are made as POST
- POST requests have Content-Type as text/plain
- $ct URL param presents actual Content-Type
- $m URL param presents actual Cotnent-Type
Change-Id: I860bb84b30a2259d750a2239b7713c019b89b0e0
d8d91278b2