[omnibox] Update the icon's colors on theme change

Icons, like a bookmark star, weren't getting updated when flipping
between light and dark e.g. on a Mac. This CL changes the behavior to
update them on a theme change.

Bug: 935265
Change-Id: I3b7a3827690c76815772a45c385ce08fa7dce73d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1584401
Reviewed-by: Tommy Li <tommycli@chromium.org>
Commit-Queue: Kevin Bailey <krb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654168}
1 file changed