This change fills the font-family, font-size, font-weight, italic, bold
and color attributes of the AXNode with exposed values from the PDFium
APIs.

I've also added a PDF accessibility tree dump test using the filter
properties to dump those attributes in the expected file. The test file
is "text-style.pdf".

Somehow, I added in a previous change text-format-expected-blink.txt.
This file should have never been committed. I removed it in this CL.

Bug: 985604
Change-Id: I70a4729269aea69e184e61710d7977425b431704
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1755412Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Ian Prest <iapres@microsoft.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711942}