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- Implemented firing property changed event for
  UIA_AriaPropertiesPropertyId - hidden upon visibility change
  introduced by aria-hidden and visibility:hidden, accompanied by
  associated browser dump tests.

- Documentation on UI Automation AriaProperties
(see the second table's last column for AriaProperties
properties):
https://docs.microsoft.com/en-us/windows/desktop/WinAuto/uiauto-ariaspecification

Bug: 928949
Change-Id: I7808ba8fe352d515a054027217afc34892b38732
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1659970
Commit-Queue: Victor Fei <vicfei@microsoft.com>
Reviewed-by: Katie Dektar <katie@chromium.org>
Reviewed-by: Ian Prest <iapres@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#675876}