CCA: Supports dynamic color

Add basic code to listen for dynamic color changes and migrate two
simple things into using dynamic color tokens as a poc. All colors will
be migrated in a series of follow up CLs.

Bug: b:228796439
Test: enable chrome://flags#jelly-colors, and check the icon and
background are of expected color.

Change-Id: I7f1b909db3c68e20aad2d2cad065170bca7266c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4374510
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Pi-Hsun Shih <pihsun@chromium.org>
Reviewed-by: Shik Chen <shik@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1132300}