Add aria-current state to Automation API.

This will allow ChromeVox to expose aria-current state
to users.

Bug: 1150076
Change-Id: I4aee64948c7a474650514d9edec68b655125df74
AX-Relnotes: N/A
Test: Tried node.ariaCurrentState from chromevox background page
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2774055
Commit-Queue: Katie Dektar <katie@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#864915}
GitOrigin-RevId: 828358dfed86c30da261e32f8b0503dd24cb531b
1 file changed