The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3d9b5b94d0649d6a2b0fb3c9e716476bec291208

commit 3d9b5b94d0649d6a2b0fb3c9e716476bec291208
Author: Dominic Mazzoni <dmazzoni@chromium.org>
Date: Wed Apr 18 21:36:38 2018

Introduce AXTableInfo to compute info about tables from an AXTree.

This new class computes information about a table in an AXTree,
including its dimensions, headers, and a mapping from row/column
index to a cell's node ID. It's computed from an AXTree on-demand
and cached until the tree changes.

Subsequent changes will switch browser-side code to use this
interface instead of the equivalent information provided by Blink,
and then remove some of the table-handling code from Blink.

See bug 832289 for more details on the planned refactoring.

Bug: 832289, 651614, 789748, 753125,
Change-Id: I29b31833426b69cb73266829e8f577785aa6fce6
Reviewed-on: https://chromium-review.googlesource.com/1011229
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551832}
[modify] https://crrev.com/3d9b5b94d0649d6a2b0fb3c9e716476bec291208/ui/accessibility/BUILD.gn
[add] https://crrev.com/3d9b5b94d0649d6a2b0fb3c9e716476bec291208/ui/accessibility/ax_table_info.cc
[add] https://crrev.com/3d9b5b94d0649d6a2b0fb3c9e716476bec291208/ui/accessibility/ax_table_info.h
[add] https://crrev.com/3d9b5b94d0649d6a2b0fb3c9e716476bec291208/ui/accessibility/ax_table_info_unittest.cc
[modify] https://crrev.com/3d9b5b94d0649d6a2b0fb3c9e716476bec291208/ui/accessibility/ax_tree.cc
[modify] https://crrev.com/3d9b5b94d0649d6a2b0fb3c9e716476bec291208/ui/accessibility/ax_tree.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/65582a0a4cdbd7200afa163cdfb542236e5c3a55

commit 65582a0a4cdbd7200afa163cdfb542236e5c3a55
Author: Dominic Mazzoni <dmazzoni@chromium.org>
Date: Tue Apr 24 23:21:35 2018

Use AXTableInfo to dynamically compute table properties.

This is a follow-up to http://crrev.com/c/1011229, which introduced
AXTableInfo. In this change, Mac and Windows accessibility code uses
AXTableInfo to get cell IDs, column headers, and row headers, rather
than relying on those attributes from Blink.

This speeds up Blink serialization and will make it easier for our
table handling code to be even more fast and robust.

TBR=estark@chromium.org

Bug: 832289, 651614, 789748, 753125
Change-Id: I4d859e0a5973f172b1b3e587ad871607d127f6cd
Reviewed-on: https://chromium-review.googlesource.com/1012447
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553354}
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/content/browser/accessibility/browser_accessibility.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/content/browser/accessibility/browser_accessibility.h
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/content/browser/accessibility/browser_accessibility_cocoa.mm
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/content/browser/accessibility/browser_accessibility_manager.h
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/content/browser/accessibility/cross_platform_accessibility_browsertest.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/content/renderer/accessibility/blink_ax_tree_source.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/content/test/data/accessibility/aria/table-column-hidden-expected-blink.txt
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/ax_enum_util.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/ax_enums.mojom
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/ax_node_data.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/ax_tree_combiner_unittest.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/ax_platform_node_base.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/ax_platform_node_delegate.h
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/ax_platform_node_unittest.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/ax_platform_node_win.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/ax_platform_node_win_unittest.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/ax_system_caret_win.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/ax_system_caret_win.h
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/test_ax_node_wrapper.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/accessibility/platform/test_ax_node_wrapper.h
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/views/accessibility/native_view_accessibility_auralinux.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/views/accessibility/native_view_accessibility_base.cc
[modify] https://crrev.com/65582a0a4cdbd7200afa163cdfb542236e5c3a55/ui/views/accessibility/native_view_accessibility_base.h

Might be fixed? Would like to check to see if this can still be reproduced.

This issue still repros.
No change between
Chrome: 70.0.3538.67 (Official Build) (64-bit) (cohort: 70_67_Win)
Chrome: 72.0.3588.0 (Official Build) canary (64-bit) (cohort: Clang-64)

Only the last row header is announced as a row header with JAWS 2018

Strangely, NVDA 2018.3.2 only reads '50' for this cell and 'rowhead' for the other cells in column 1 where JAWS reads 20, 20, 30, 40, 50