GitLab

Essentially, for each color in question, this creates a new colorset
that is only the dark mode variant of the color always. Then, if we're
running on iOS 12 and in incognito, we return that new color.

Bug: 976643
Change-Id: I14ede8cb4280af7f960d53880712d74f8e4564b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1710539Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Cr-Commit-Position: refs/heads/master@{#680477}