ARIA 1.1: implementation for aria-col-* and aria-row-*.
This patch adds implementation for aria-col-index, aria-col-count, aria-
col-span, aria-row-index, aria-row-count, aria-row-span from ARIA 1.1,
https://rawgit.com/w3c/aria/master/aria/aria.html.
For windows, aria-col-count, aria-col-index, aria-row-count, aria-row-
index, aria-col-span and aria-row-span are exposed as object attributes.
Based on
http://codereview.chromium.org/1547643002 by je_julie,
which was in turn based on wkrev.com/190833 by n_wang.
BUG=
543050,
644766
Committed:
https://crrev.com/c5d4f1b146e762edcc6a86dd880c95da651d71d3
Cr-Commit-Position: refs/heads/master@{#440852}