MD Settings: reduce amount of focus ripples shown by mouse

Upstream PR for paper-icon-button(-light):
https://github.com/PolymerElements/paper-icon-button/pull/111

R=dpapad@chromium.org
BUG=none
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2832023004
Cr-Commit-Position: refs/heads/master@{#466519}
5 files changed