The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/60315b50ff3bf925a05a017ddc6d54f7cf69d9c5

commit 60315b50ff3bf925a05a017ddc6d54f7cf69d9c5
Author: Martin Robinson <mrobinson@igalia.com>
Date: Wed Dec 05 10:12:55 2018

Add support for the AtkSelection interface

Bug:  907499 
Change-Id: I2e5135ca4fd96cbcda7832f98ea8798d13584c77
Reviewed-on: https://chromium-review.googlesource.com/c/1353945
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Martin Robinson <mrobinson@igalia.com>
Cr-Commit-Position: refs/heads/master@{#613926}
[modify] https://crrev.com/60315b50ff3bf925a05a017ddc6d54f7cf69d9c5/ui/accessibility/platform/ax_platform_node_auralinux.cc
[modify] https://crrev.com/60315b50ff3bf925a05a017ddc6d54f7cf69d9c5/ui/accessibility/platform/ax_platform_node_auralinux.h
[modify] https://crrev.com/60315b50ff3bf925a05a017ddc6d54f7cf69d9c5/ui/accessibility/platform/ax_platform_node_auralinux_unittest.cc
[modify] https://crrev.com/60315b50ff3bf925a05a017ddc6d54f7cf69d9c5/ui/accessibility/platform/test_ax_node_wrapper.cc
[modify] https://crrev.com/60315b50ff3bf925a05a017ddc6d54f7cf69d9c5/ui/accessibility/platform/test_ax_node_wrapper.h

This works great for select elements with size > 1 and page tabs. Thanks!!

I found a few more objects where AtkSelection should be implemented, plus we could use the event emission:

* https://bugs.chromium.org/p/chromium/issues/detail?id=918432
* https://bugs.chromium.org/p/chromium/issues/detail?id=918434
* https://bugs.chromium.org/p/chromium/issues/detail?id=918438