Fix uploaded but it needs a little more work especially since performance might be affected.
https://chromium-review.googlesource.com/c/chromium/src/+/1298173

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/077f8178bd8a84c709ad06a45b3e43386301e7fd

commit 077f8178bd8a84c709ad06a45b3e43386301e7fd
Author: Nektarios Paisios <nektar@chromium.org>
Date: Tue Nov 06 03:43:25 2018

Updates the accessibility tree when style changes dynamically

This patch also fixes the bug whereby Jaws wasn't announcing the visited state on a link.
We need to update the accessibility tree if there are any changes to the way a layout object is painted.
To be safe, we update the whole subtree.
The update needs to happen after the style change, not before, so as to catch any changes to the visited link state, color and font.
R=dmazzoni@chromium.org, aleventhal@chromium.org

Change-Id: I03f512a95f8101c603a712fb3d62e7b31a59da5e
Bug:  898706 
Reviewed-on: https://chromium-review.googlesource.com/c/1298173
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605585}
[modify] https://crrev.com/077f8178bd8a84c709ad06a45b3e43386301e7fd/content/shell/test_runner/web_ax_object_proxy.cc
[modify] https://crrev.com/077f8178bd8a84c709ad06a45b3e43386301e7fd/content/shell/test_runner/web_ax_object_proxy.h
[add] https://crrev.com/077f8178bd8a84c709ad06a45b3e43386301e7fd/third_party/WebKit/LayoutTests/accessibility/color-changed.html
[add] https://crrev.com/077f8178bd8a84c709ad06a45b3e43386301e7fd/third_party/WebKit/LayoutTests/accessibility/font-changed.html
[modify] https://crrev.com/077f8178bd8a84c709ad06a45b3e43386301e7fd/third_party/blink/renderer/core/layout/layout_object.cc

To verify first start Jaws any version:
1. Open a page containing unvisited links, e.g. perform a search for something new on Google.
2. Find an unvisited link using tab or "u" (the quick nav shortcut for Unvisited links).
3. Either press Ctrl+Enter or Shift+Enter to open the link in a new tab / page respectively. Just perform one of those actions, not both.
4. Alt+Tab back to the original page.
5. Verify that Jaws reads "Visited" when announcing the link.