Changing the OS since you mentioned TalkBack, I am assuming you meant on Android, not Linux.

Tested on Pixel 2 XL Android 8.1.0 Build/OPM2.171019.029 and observed the following behavior on latest Chrome stable #66.0.3359.106:

1. Launched Chrome with Talkback enabled on the device.
2. Navigated to the URL - https://mounirlamouri.github.io/sandbox/a11y-tests.html
3. Below are the observations - 

1. Two slider bars are displayed and respective audio is displayed.
2. Tapped on 'foo' button - heard 'foo button double tap to activate'
3. Tapped on 'bar' button - heard 'bar button'
4. Tapped on 'bob' button - heard 'bob button disabled'
5. Tapped on 'bip' button - heard 'bip button'

mlamouri@ -- Above are the observations. Could you please let us know whether they are the expected or not. If there are any differences, could you please let us know the expected results. This would help us in further triaging the issue.

Thanks!

It should be:
1. Two slider bars are displayed and respective audio is displayed.
2. Tapped on 'foo' button - heard 'foo button double tap to activate'
3. Tapped on 'bar' button - heard 'bar button disabled'
4. Tapped on 'bob' button - heard 'bob button disabled'
5. Tapped on 'bip' button - heard 'bip button disabled'

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

Tested the issue in Android and able to reproduce the issue. 

Steps Followed:
1. Launch Chrome with 'Talkback' enabled on device.
2. Navigate to any URL - https://mounirlamouri.github.io/sandbox/a11y-tests.html
3. Tap on the buttons 'bar' and 'bip'
4. Observed that voice heard on tapping either of the above buttons is 'bar/bip button' instead of 'bar/bip button disabled'

Chrome versions tested:
66.0.3359.126(Stable), 68.0.3405.0(Canary)

OS:
Android 8.1.0

Android Devices:
Pixel 2 XL

Using the per-revision bisect providing the bisect results,
Good Build - 62.0.3194.0 (496533)
Bad Build - 62.0.3196.0 (497279)

You are looking for a change made after 496847(GOOD), but before 496848(BAD).

CHANGELOG URL:
The script might not always return single CL as suspect as some perf builds might get missing due to failure.
https://chromium.googlesource.com/chromium/src/+/3c944b9a8936705ca717477395531942ca02f641

@nektar:  Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to owner concerned.

Please navigate to below link for log's and video--
go/chrome-androidlogs/827805


Thanks!

Since this is a recent regression, can we have a fix during M68 time frame?

Any update here necktar@?

Pinging again!

the way I understand this bug, The disabled state is not announced on non focusable elements. If something is not focusable, it's not actionable anyway, so what information is the user missing?
Should we lower the priority and not block the release?

The issue is that Talkback doesn't expose that the element isn't focusable and it will focus it regardless.

I don't understand what is meant by "would focus it regardless".
If something is not focusable, it can't be focused. The active element can't be set to it.
If you are referring to the focus highlight, the user should be able to browse through all elements and highlight them, regardless of their disabled state, because they might be using an external keyboard or a switch, and they won't want to miss any element while reading through, even disabled elements.

The last part is actually the issue: if an element is disabled, a user that can't see it will not know it is disabled because TalkBack will announce it exactly like a regular element except that it will not say "double tap to activate". I don't use TalkBack myself so I can't judge how painful that is but instinctively, having to rely on something not being mentioned doesn't seem to be the best user experience.

FWIW, this was reported by lpalmaro@ when reviewing the new media controls in Chrome.

You are right that it's not a good user experience. My question is whether it should be release blocking or not?

Oh sorry, I don't think so. It seems to be a regression from M62 so it should be fixed but doesn't need to happen *now*. It's probably fine to drop RBS based on this.

https://chromium-review.googlesource.com/c/chromium/src/+/1410168

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/52497ad2efb4bc59887cbc66e9426bd5abb02da3

commit 52497ad2efb4bc59887cbc66e9426bd5abb02da3
Author: Dominic Mazzoni <dmazzoni@chromium.org>
Date: Wed Jan 16 06:47:00 2019

Disabled form controls should not be exposed as clickable on Android.

Based on the history of  bug 827805 , a change was made to expose
the "clickable" attribute on more nodes. This had the effect of
causing Android to announce that certain controls are clickable
even though they're disabled.

The fix is to make clickable and disabled mutually exclusive on
Android. If a node is disabled, we shouldn't expose it as clickable.

Bug:  827805 
Change-Id: Ica9417252325f405aa875e339b909fcbbc87b659
Reviewed-on: https://chromium-review.googlesource.com/c/1410168
Reviewed-by: Alice Boxhall <aboxhall@chromium.org>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623140}
[modify] https://crrev.com/52497ad2efb4bc59887cbc66e9426bd5abb02da3/content/browser/accessibility/browser_accessibility_android.cc
[modify] https://crrev.com/52497ad2efb4bc59887cbc66e9426bd5abb02da3/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
[modify] https://crrev.com/52497ad2efb4bc59887cbc66e9426bd5abb02da3/content/test/data/accessibility/aria/aria-disabled-expected-android.txt
[add] https://crrev.com/52497ad2efb4bc59887cbc66e9426bd5abb02da3/content/test/data/accessibility/html/disabled-expected-android.txt
[add] https://crrev.com/52497ad2efb4bc59887cbc66e9426bd5abb02da3/content/test/data/accessibility/html/disabled-expected-blink.txt
[add] https://crrev.com/52497ad2efb4bc59887cbc66e9426bd5abb02da3/content/test/data/accessibility/html/disabled.html