Add DumpAccessibilityTree tests (5 of 20).

HTML Tags: head, input type tel, noscript
ARIA Role: listbox, separator
ARIA state/property: aria-required(true/false)

Following HTML tags are undergoing/done in some other CL:
HTML Tag - input type num, pre, header, blockquote.

HTML ruby tag is not exposed correctly. Will submit it with the fix in new CL.

BUG=170577

Review URL: https://codereview.chromium.org/680483002

Cr-Commit-Position: refs/heads/master@{#301115}
25 files changed