GitLab

Adds examples of creating a WebUIConfig and an UntrustedWebUIController
for chrome-untrusted:// WebUIs.

Bug: 1080384
Change-Id: I8927c134ecdf015524b34a5cb5c88f1c03bccde7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2596900Reviewed-by: Nasko Oskov <nasko@chromium.org>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839047}