The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/92c1c5cbd4dd4c11e4c7be7c0cf1aa911d19053a

commit 92c1c5cbd4dd4c11e4c7be7c0cf1aa911d19053a
Author: Aaron Leventhal <aleventhal@chromium.org>
Date: Sat Jun 09 02:53:12 2018

Support accessibility attribute AXSelected on Mac

Bug:  851089 
Change-Id: Ibc6bd65d7a307fcad84e8720bf81885ad6a03723
Reviewed-on: https://chromium-review.googlesource.com/1091961
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565828}
[modify] https://crrev.com/92c1c5cbd4dd4c11e4c7be7c0cf1aa911d19053a/content/browser/accessibility/accessibility_tree_formatter_mac.mm
[modify] https://crrev.com/92c1c5cbd4dd4c11e4c7be7c0cf1aa911d19053a/content/browser/accessibility/browser_accessibility_cocoa.mm
[modify] https://crrev.com/92c1c5cbd4dd4c11e4c7be7c0cf1aa911d19053a/content/test/data/accessibility/aria/aria-selected-expected-mac.txt
[modify] https://crrev.com/92c1c5cbd4dd4c11e4c7be7c0cf1aa911d19053a/content/test/data/accessibility/aria/aria-selected.html
[modify] https://crrev.com/92c1c5cbd4dd4c11e4c7be7c0cf1aa911d19053a/ui/accessibility/platform/ax_platform_node_mac.mm