CSS Layers test tool

To reproduce https://bugs.chromium.org/p/chromium/issues/detail?id=1338543

What steps will reproduce the problem?

Creat basic HTML page with <style>@layer base, layout, component, state, theme;</style>

  1. add @import url('styles.css') layer(state); to <style>
  2. add <link rel="stylesheet" media="all" href="styles.css" layer="theme" />

Check Dev Tools.

What is the expected result?

a) Layer button shows up in dev tools. Everything as expected (Described in https://developer.chrome.com/blog/new-in-devtools-101/#layer)

b) No layer Button shows up. No defined layers in dev tools

Now I see: It's not part of the "supported" implementation :/

whatwg/html#7540

Chrome Page on it

https://developer.chrome.com/blog/new-in-devtools-101/#layer