Revert "Implement CSSTransitionDiscrete which enables transitions on …

…discrete properties."

This reverts commit 367c58094d184ff90ef132789985bd4fc53c721a.

Reason for revert: Causing failures in blink-web-tests on many bots, for example: https://ci.chromium.org/ui/p/chromium/builders/ci/Linux%20Tests/127213/overview

Original change's description:
> Implement CSSTransitionDiscrete which enables transitions on discrete properties.
>
> This feature enables transitioning discrete properties.
>
> This is based on the resolved CSSWG issue:
> - Transition discrete properties: w3c/csswg-drafts#4441
>
> You can test display transitions with this CL on:
> https://output.jsbin.com/buquher/quiet
>
> Original patch: http://crrev.com/c/4182089
>
> Bug: 1399631, 1413556
> Change-Id: Icf5364b970233186794fa9faaa016e0e6542ec2b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4219315
> Reviewed-by: Robert Flack <flackr@chromium.org>
> Commit-Queue: Joey Arhar <jarhar@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1112645}

Bug: 1399631, 1413556
Change-Id: I45cbf126b16402a88c7105d8204b342a79ded3d5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4305045
Commit-Queue: Adam Rice <ricea@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Adam Rice <ricea@google.com>
Cr-Commit-Position: refs/heads/main@{#1112668}