The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6a11adfcb5d83a4de1225e28be2ddf516c80e38a

commit 6a11adfcb5d83a4de1225e28be2ddf516c80e38a
Author: Martin Robinson <mrobinson@igalia.com>
Date: Thu Jan 10 08:53:17 2019

Map accessible relations to AtkRelationSet

This adds support for mapping relations and reverse relations to ATK
equivalents. Relations are calculated by maintaining a table of
attribute to relation mappings with an optional reverse relation. We
step through these tables and test each attribute, adding it to the
relation set if necessary.

Bug:  915453 
Change-Id: I6d7db60009fd4d302c457098d5a0256ef6ea7647
Reviewed-on: https://chromium-review.googlesource.com/c/1378977
Commit-Queue: Martin Robinson <mrobinson@igalia.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621507}
[modify] https://crrev.com/6a11adfcb5d83a4de1225e28be2ddf516c80e38a/ui/accessibility/platform/ax_platform_node_auralinux.cc
[modify] https://crrev.com/6a11adfcb5d83a4de1225e28be2ddf516c80e38a/ui/accessibility/platform/ax_platform_node_auralinux.h
[modify] https://crrev.com/6a11adfcb5d83a4de1225e28be2ddf516c80e38a/ui/accessibility/platform/ax_platform_node_auralinux_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fed343aa4432686bdf6505996f057c1c91185463

commit fed343aa4432686bdf6505996f057c1c91185463
Author: Daniel Bratell <bratell@opera.com>
Date: Mon Jan 14 18:03:24 2019

Add some ATK version number checks on new ATK members.

Ubuntu 16.04 LTS still has an old version of atk (2.18.0) so
to be able to build on Ubuntu 16.04 without a sysroot, this
adds version checks for some of the new relations:
ATK_RELATION_DETAILS, ATK_RELATION_DETAILS_FOR,
ATK_RELATION_ERROR_MESSAGE and ATK_RELATION_ERROR_FOR.

Bug:  915453 
Change-Id: I1ee0a4d0edcb128e225579138aa65df0b0f307db
Reviewed-on: https://chromium-review.googlesource.com/c/1409445
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Martin Robinson <mrobinson@igalia.com>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#622508}
[modify] https://crrev.com/fed343aa4432686bdf6505996f057c1c91185463/ui/accessibility/platform/ax_platform_node_auralinux.cc