GitLab

Introduces new generated preference to support the Quad state radio
button which controls the primary cookie settings on the new Cookies
page.

This CL creates the generated preference and extends
settings_private.idl with a new userSelectableValues attribute to
support the complex partial management states this preference must be
capable of representing.

The new preference is not used in production code and only enough
management state functionality is included to test the additions to the
SettingsPrivate API.

Bug: 1063265
Change-Id: I15ac79021530efe6af11cb000f536549216263ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2199461Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Martin Šrámek <msramek@chromium.org>
Commit-Queue: Theodore Olsauskas-Warren <sauski@google.com>
Cr-Commit-Position: refs/heads/master@{#771432}