GitLab

This patch adds a basic Chrome OS settings page for the ambient mode.
Two settings added:
1. A top level toggle to enable/disable the ambient mode.
2. A radio button group to choose the topic source, e.g. Google photos.

Bug: b/151372242
Test: new browser tests
Change-Id: Ifeda979080b33a5d42643b010e39d5e15b31c2e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2102008Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Yue Li <updowndota@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Commit-Queue: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#753258}