The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0

commit 6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0
Author: Aaron Leventhal <aleventhal@chromium.org>
Date: Fri Jul 07 18:22:15 2017

Don't expose native mixed radios as ax mixed

Do not expose native radio mixed state as accessibility mixed state, because
this confuses the JAWS screen reader, which reports a mixed radio as
both checked and partially checked. A native mixed native radio
button sinply means no radio buttons have been checked in the group yet.

Bug:  739752 
Change-Id: Icdfc404b6d50d1ecb25b5b3221c79ba0da2f7400
Reviewed-on: https://chromium-review.googlesource.com/561817
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#484990}
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/content/test/data/accessibility/aria/aria-posinset-expected-blink.txt
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/content/test/data/accessibility/aria/aria-posinset-expected-mac.txt
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/content/test/data/accessibility/aria/aria-posinset-expected-win.txt
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/content/test/data/accessibility/html/action-verbs-expected-blink.txt
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/content/test/data/accessibility/html/input-radio-expected-blink.txt
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/content/test/data/accessibility/html/input-radio-expected-mac.txt
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/content/test/data/accessibility/html/input-radio-expected-win.txt
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/third_party/WebKit/LayoutTests/accessibility/input-mixed.html
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
[modify] https://crrev.com/6bee55cdbe806e2893ea4fe1a69ac2313b97d2b0/third_party/WebKit/Source/modules/accessibility/AXObject.h