Thanks for filing the issue!

Checked the issue on reported chrome version 65.0.3325.162 using Mac 10.13.1 with the below mentioned steps.
1. Launched chrome
2. Downloaded "	aria-expanded_chrome-vo.html " file.
3. Tried opening the file in a new tab.
It says "It may have been moved or deleted". Attaching the screen cast of the same.

@Reporter: Could you please have a look at the screen cast and let us know if we have missed anything in the process. Providing with another test file would help us in triaging the issue in a better way.
  

Deleted: 824465.mp4 5.4 MB

	824465.mp4 5.4 MB View Download

Here’s a live demo of the test case: https://codepen.io/Wilto/live/XERjbz

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

Able to reproduce the issue on reported chrome version 65.0.3325.162 and on the latest canary 67.0.3378.0 using Mac 10.13.1.
Note: Couldn't check on other OS as VoiceOver is part of Apple's accessibility features.

Bisect Information:
====================
Last Good Build: 65.0.3293.0
First Bad Build: 65.0.3294.0

You are probably looking for a change made after 523875 (known good), but no later than 523876 (first known bad).
CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/d1f8c228bd7e1827e1bcb65635ea8550cc95f0b1..5ee1df851433b068389042402a074aecd8df1002

Suspecting: https://chromium.googlesource.com/chromium/src/+/5ee1df851433b068389042402a074aecd8df1002

Review URL: https://chromium-review.googlesource.com/810344

@Dominic Mazzoni: Please help in re-assigning it to the right owner, if this is not related to your change.
Assigning it to Dominic Mazzoni as Deejay Kim isn't available.

Note: Adding RB-Stable as this seems to be a recent regression, please remove if not applicable.

Thanks!

Changing target milestone to 66

Dear @dominic,
It looks that is related my previous patch-set. Can I take this issue?

Dear all,
I've updated patch as below.

https://chromium-review.googlesource.com/c/chromium/src/+/989633

Just a heads up, M66 Stable cut is on April 12th, 10 days away. This issue is marked as RB-Stable for 66. Please make sure to address this issue prior to stable cut. Thanks! 

I can repro this in windows as well
Chrome: 67.0.3387.0 
Chrome: 65.0.3325.181 
Chrome: 56.0.2924.0 
Firefox: 52 ESR
JAWS: 2018
NVDA: 2018.1.1

Steps to repro:
# Open attached file using JAWS or NVDA
# Explore with down arrow
# Note the state of each button and link

Expected: 'expanded' or 'collapsed' is announced when aria-expanded is set to 'true' or 'false'
Firefox: Works as expected

Actual: It is not announced.
Chrome 56: works as expected

Deleted: aria-expanded and pressed.html 462 bytes

aria-expanded and pressed.html 462 bytes View Download

 Issue 728345  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cd1f4d368d244d5cc94a9e6928f79e76c7032e25

commit cd1f4d368d244d5cc94a9e6928f79e76c7032e25
Author: DongJun Kim <djmix.kim@samsung.com>
Date: Wed Apr 04 18:47:06 2018

fixup! Introduce SupportsARIAExpanded() for aria-expanded

Chrome/VoiceOver didn't narrates `aria-expanded` state in latest code.
We fix from AriaRoleAttribute() to RoleValue() in SupportsARIAExpanded.

Bug:  824465 
Change-Id: Ib9ded5bbf84ad59f96cd2eb06cdd18eb537d8224
Reviewed-on: https://chromium-review.googlesource.com/989633
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548140}
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/content/test/data/accessibility/html/action-verbs-expected-blink.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/content/test/data/accessibility/html/action-verbs-expected-win.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/content/test/data/accessibility/html/details-expected-blink.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/content/test/data/accessibility/html/details-expected-mac.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/content/test/data/accessibility/html/details-expected-win.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/content/test/data/accessibility/html/summary-expected-blink.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/content/test/data/accessibility/html/summary-expected-win.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/third_party/WebKit/LayoutTests/inspector-protocol/accessibility/accessibility-nameSources-summary-expected.txt
[modify] https://crrev.com/cd1f4d368d244d5cc94a9e6928f79e76c7032e25/third_party/WebKit/Source/modules/accessibility/AXObject.cpp

@dsexton to verify.

Let's either merge to M66 ASAP, or just remove the release block.

Would be nice to merge as this was a regression reported by multiple users and the fix is small.

This bug requires manual review: We are only 7 days from stable.
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), josafat@(ChromeOS), abdulsyed@(Desktop)

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

Approving merge to M66. Branch:3359 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6bd1af0d2704f223edabaee232c4c3d1f552e720

commit 6bd1af0d2704f223edabaee232c4c3d1f552e720
Author: DongJun Kim <djmix.kim@samsung.com>
Date: Wed Apr 11 20:56:23 2018

Merge to M66: fixup! Introduce SupportsARIAExpanded() for aria-expanded

Chrome/VoiceOver didn't narrates `aria-expanded` state in latest code.
We fix from AriaRoleAttribute() to RoleValue() in SupportsARIAExpanded.

Bug:  824465 
Change-Id: Ib9ded5bbf84ad59f96cd2eb06cdd18eb537d8224
Reviewed-on: https://chromium-review.googlesource.com/989633
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#548140}(cherry picked from commit cd1f4d368d244d5cc94a9e6928f79e76c7032e25)
Reviewed-on: https://chromium-review.googlesource.com/1008463
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/branch-heads/3359@{#690}
Cr-Branched-From: 66afc5e5d10127546cc4b98b9117aff588b5e66b-refs/heads/master@{#540276}
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/content/test/data/accessibility/html/action-verbs-expected-blink.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/content/test/data/accessibility/html/action-verbs-expected-win.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/content/test/data/accessibility/html/details-expected-blink.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/content/test/data/accessibility/html/details-expected-mac.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/content/test/data/accessibility/html/details-expected-win.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/content/test/data/accessibility/html/summary-expected-blink.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/content/test/data/accessibility/html/summary-expected-win.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/third_party/WebKit/LayoutTests/inspector-protocol/accessibility/accessibility-nameSources-summary-expected.txt
[modify] https://crrev.com/6bd1af0d2704f223edabaee232c4c3d1f552e720/third_party/WebKit/Source/modules/accessibility/AXObject.cpp

Verified the fix on Mac 10.13.1 using Voice over and on Windows-10 using JAWS on chrome version 66.0.3359.117 as per the comment #0.
Attaching screen cast for reference.
Observed that Toggle button was narrated by VoiceOver as “toggle, expanded, button.”
Hence, the fix is working as expected. 
Adding the verified labels.
Note: Able to reproduce the issue on chrome version 65.0.3325.162.

Thanks...!!