Steps:
1. Launch JAWS screen reader
2. Go to https://github.com/GoogleChrome/chrome-app-samples
3. Press T

JAWS reports "no tables on this page".

This is because the table is styled as display:block. However, JAWS has requested that will still expose the tr object with a BSTR "TR" role, similar to what we do for the "table" and "td" objects. 

This should be low-hanging fruit and a good first bug for someone wanting to get started in accessibility. It's probably a patch in AXObjectCacheImpl to make sure that a tr still gets an AXLayoutObject if it's not a real CSS table row or not part of a real CSS table.