Implement ImageAnnotationStatus for accessibility on Windows.

Introduces a new accessibility attribute, ImageAnnotationStatus,
representing the state of automatic annotations on an image.
Based on the status of this attribute, augments the name
and role description of a node for Windows, using localized
strings.

The status will eventually need to be populated by
BlinkAXTreeSource.

TBR=rockot@chromium.org

Bug: 905419

Change-Id: I310be8669ea032cb8ec13c56fbc11bc0ffee53fd
Reviewed-on: https://chromium-review.googlesource.com/c/1471353
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Katie Dektar <katie@chromium.org>
Reviewed-by: Will Harris <wfh@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633025}
19 files changed