Implement 5 ARIA 1.1 roles: cell, feed, figure, table, term

These 5 roles are all defined in the ARIA 1.1 editor's draft.
All 5 are quite trivial because we either already supported
them as a native HTML role, or we just pass them through
to assistive technology without affecting any semantics.

The spec is defined here:
https://rawgit.com/w3c/aria/master/aria/aria.html

The test expectations were checked against the latest
draft of the Core Accessibility API Mappings:
http://w3c.github.io/aria/core-aam/core-aam.html

BUG=644766

Review-Url: https://codereview.chromium.org/2607113003
Cr-Commit-Position: refs/heads/master@{#442199}
26 files changed