DevTools: Expose more properties through the accessibility protocol

This adds the new properties:
	invisible
	editable
	focusable
	focused
	settable

Bug: 887173
Change-Id: Iaa9dc346d10648ada9d16c6a3568f83fdd83f397
Reviewed-on: https://chromium-review.googlesource.com/c/1244548
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Alice Boxhall <aboxhall@chromium.org>
Commit-Queue: Joel Einbinder <einbinder@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599769}
14 files changed