I can repro - @dbeam, any suggestions who could look at this?

there have been touch-specific issues that have cropped up lately, but I can't tell the particular issue from your screenshots.

i'll try on my canary pixel

it seems to me that the ring might represent control focus and maybe not ripple animation at all.

it's strange that it's inconsistently appearing when using touch.

Is this actually OS=Chrome specific, or just more noticeable on slower CrOS systems?

As discussed offline, there is a patch by egarciad@ here:

https://github.com/PolymerElements/paper-ripple/tree/fast-ripple

I have tested it on a couple of slow Chrome OS devices and there is a definite noticeable improvement in smoothness.

There are two major artifacts that will be worked on:

1. Once a button has rippled, hiding then showing the button will cause the ripple to show again when the button is shown.
* e.g. expand Languages and input > Spell check, toggle English on and off, then unexpand/expand the section.
* On Chrome OS, expand/unexpand WiFi networks, then disable/enable WiFi. The expand button will ripple when it is shown.

2. Double-click (or two rapid clicks?) causes the ripple to persist and not disappear.

There are a couple minor visual artifacts with the new ripple that need UX feedback (i.e. it's not clear that the new behavior is bad, just different):

3. The ripples are faster, closer to .5 seconds than 1 second.

4. The ripple is more subtle / translucent.

dbeam@ - You also mentioned some artifacts that you noticed, is there anything you noticed that I missed?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8c3875d433e85fc3868d5aa1f0350c0127175973

commit 8c3875d433e85fc3868d5aa1f0350c0127175973
Author: dbeam <dbeam@chromium.org>
Date: Fri Feb 24 02:58:38 2017

MD WebUI: create a Chrome-only <paper-ripple> that's resistant to JS jank (via web animations API)

BUG= 669592 
R=dpapad@chromium.org

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2691393005
Cr-Commit-Position: refs/heads/master@{#452727}

[modify] https://crrev.com/8c3875d433e85fc3868d5aa1f0350c0127175973/third_party/polymer/README.chromium
[modify] https://crrev.com/8c3875d433e85fc3868d5aa1f0350c0127175973/third_party/polymer/v1_0/components-chromium/paper-ripple/paper-ripple-extracted.js
[modify] https://crrev.com/8c3875d433e85fc3868d5aa1f0350c0127175973/third_party/polymer/v1_0/components-chromium/paper-ripple/paper-ripple.html
[modify] https://crrev.com/8c3875d433e85fc3868d5aa1f0350c0127175973/ui/file_manager/file_manager/foreground/elements/compiled_resources2.gyp
[modify] https://crrev.com/8c3875d433e85fc3868d5aa1f0350c0127175973/ui/file_manager/file_manager/foreground/elements/files_ripple.js

stevenjb@: can you try this soon?