Chrome Version: 61.0.3122.0 (Official Build) canary(64-bit)
OS: Windows 10 Version 1703 (OS Build 16199.1000) 64-bit

What steps will reproduce the problem?
(1) Start Chrome and the NVDA screen reader.
(2) Open this URL: data:text/html,before<div role="table"><div role="row"><div role="cell">A</div><div role="cell">B</div></div></div>
(3) Press control+home, then down arrow to move to the table.
Expected: NVDA should say "table with 1 rows and 2 columns  row 1 column 1  A"
Actual: NVDA says "table with 0 rows and 0 columns  row 1 column 1  A"
(4) Press down arrow.
Expected: NVDA should say "column 2  B"
Actual: NVDA says just "B"

IAccessibleTable2::nRows and IAccessible2::nColumns both report 0 for this table. They should report 1 and 2 respectively. IAccessibleTableCell::rowNumber and columnNumber both report 0 for both cells. columnNumber should report 1 for the second cell.

I've used these new roles in the GitHub axSGrease script (https://github.com/nvaccess/axSGrease) to make otherwise inaccessible GitHub tables accessible. This works in Firefox, but not in Chrome (because of this bug).