GitLab

This change:
1) Draws exterior borders on menus, even if MenuConfig says not to use them,
   if the NativeTheme is in high contrast mode;
2) Draws separators in black instead of grey in high contrast mode on Mac;
3) Draws a heavy (2pt) border around the selected item in high contrast mode
   on Mac

Screenshots are attached to the bug as comment #10.

Bug: 829347
Change-Id: I8ffd7adbae5b35751c18b77a9e8b6564926f7012
Reviewed-on: https://chromium-review.googlesource.com/1010245
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551324}