GitLab

This is part of supporting translation for sub frames.
Specifically this moves the analysis of the untrusted contents
obtained from an accessiblity tree snapshot out of the browser
process and into a sandboxed utility process.

Bug: 1063520
Change-Id: I0792d209541558a753f168f78f421e66745748d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2140605
Commit-Queue: Doug Arnett <dougarnett@chromium.org>
Reviewed-by: anthonyvd <anthonyvd@chromium.org>
Reviewed-by: Megan Jablonski <megjablon@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760958}