Revert "Port VR UI visibility status code to Windows"

This reverts commit 03a10a29c82cbd1f69317ce5490a2e39d478b840.

Reason for revert: https://crbug.com/921739 is getting hit very frequently on one bot.

Original change's description:
> Port VR UI visibility status code to Windows
> 
> Ports the portion of the native VR UI interaction test code that allows
> waiting on a UI element to reach a desired visibility state to the
> XR browser test framework.
> 
> Also adds a test using this that ensures a notification is displayed
> in the headset when a permission prompt is displayed in the browser.
> 
> Also fixes several issues in production code that were caught by the
> test:
> 1. Added a name to the notification UI element.
> 2. Added early returns when interacting with the notification/overlay
>    if the mojo interface is not bound, which could happen if Chrome
>    was closed while still in VR with a notification displayed.
> 
> Bug: 921103
> Change-Id: Ib157ce2014132a41233f3aefde5f9521d56cf168
> Reviewed-on: https://chromium-review.googlesource.com/c/1407663
> Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
> Reviewed-by: Bill Orr <billorr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#622674}

TBR=bsheedy@chromium.org,billorr@chromium.org

Change-Id: I200b51906c0807fc909dbed9f340798cd6248129
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 921103
Reviewed-on: https://chromium-review.googlesource.com/c/1413059
Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622872}
22 files changed