GitLab

This CL updates the dark mode styles for the following controls:
1. <meter> -  border color.
2. multi-select - foreground text color.
3. Button: Dark mode button design has no border and has unique fill
   color. Thus, a specific set of color enums is created for only
   buttons. Button's border color is styled to match its fill color
   in order to give the appearance of no borders and keep its
   dimensions unchanged. This impacts: button, file, and color
   controls.


Bug: 1107290, 1099624
Change-Id: I141c199f93acac2b950b8af7195e863f811c2f4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2469357
Commit-Queue: Yu Han <yuzhehan@google.com>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Reviewed-by: Mason Freed <masonfreed@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818119}