Unable to reproduce the issue on chrome reported version# 70.0.3538.110 using Mac 10.12.6 with steps mentioned below:
1) Launched chrome reported version and navigated to URL: https://jsfiddle.net/e_ozelius/z26jm37d/9/
2) Enabled chromevox and clicked on 'my web component', chromevox read out: "my web component accessibility Label"

@Reporter: Please find the attached screencast for your reference and let us know if we missed anything in reproducing the issue, provide your feedback on it which help in further triaging it in better way.

Thanks!

Deleted: 912285.mp4 1.7 MB

	912285.mp4 1.7 MB View Download

Hello, thank you for looking into this.

You are 100% correct that the issue was not reproducible.  I have updated
the jsfiddle code example, and it should be much clearer.

Updated steps to reproduce:
1. Enable Chromevox extension -
https://chrome.google.com/webstore/detail/chromevox/kgejglhpjiefppelpmljglcjbhoiplfn
2. Navigate to https://jsfiddle.net/e_ozelius/z26jm37d/42/
3. Click second button, that has text "Regular Button".  Chromevox should
read aloud "accessibility is working on the regular button!"
4. Click the first button, that has text "Web component Button".  Chromevox
will create an orange outline, but won't read anything aloud.

This proves that chromevox does not read aloud accessible aria-labels that
are within web components, i.e. rendered as part of a #shadow-root.

Let me know if I can help any further.

Best,
Ethan.

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Good morning,

I am reaching out to you to follow up on this ticket since I updated the
jsfiddle example and make sure it will be looked into properly.

Thank you,
Ethan