Return to using icon sizes from before crrev.com/c/1243680.
This should exclude a possibility of any regressions.
Updating the icon look to the latest UI design.

Bug: 893548
Test: steps in bug
Change-Id: I596750416a5c87f0239119086b4db84554f3d3a0
Reviewed-on: https://chromium-review.googlesource.com/c/1336188Reviewed-by: Naoki Fukino <fukino@chromium.org>
Commit-Queue: Vladislav Kaznacheev <kaznacheev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608373}