The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/137817908fc7673303789ed6b0844c75191af46c

commit 137817908fc7673303789ed6b0844c75191af46c
Author: Martin Robinson <mrobinson@igalia.com>
Date: Thu Jan 17 09:50:54 2019

Reimplement atk_object_get_index_in_parent for AuraLinux

Instead of calling into the delegate to get this information, follow the
approach that Windows uses and just find the item in the parent's child
vector. This works around a problem where objects from the views code don't
properly calculate the index in their parent.

Bug:  922383 
Change-Id: I380b7a52ebde7dd77ab7d560d0a5b52e2f9bfa34
Reviewed-on: https://chromium-review.googlesource.com/c/1415250
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Martin Robinson <mrobinson@igalia.com>
Cr-Commit-Position: refs/heads/master@{#623624}
[add] https://crrev.com/137817908fc7673303789ed6b0844c75191af46c/chrome/browser/ui/views/accessibility/browser_accessibility_uitest_auralinux.cc
[modify] https://crrev.com/137817908fc7673303789ed6b0844c75191af46c/chrome/test/BUILD.gn
[modify] https://crrev.com/137817908fc7673303789ed6b0844c75191af46c/ui/accessibility/platform/ax_platform_node_auralinux.cc