Undo CSSTransitionDiscrete interpolation test changes

[chromium-wpt-export-bot]

Now that we are planning to add a new opt-in syntax for
CSSTransitionDiscrete, the test changes which I made for
CSSTransitionDiscrete will not eventually stick. Since these tests are
interop23 tracked, the other browsers would like them to be updated
ASAP.

I thought about also disabling the CSSTransitionDiscrete flag, which
would make this patch a lot cleaner, but that would break demos and
stuff people are working on so I decided against it.

This was asked for here:
#39871

CSSTransitionDiscrete opt in syntax:
w3c/csswg-drafts#8857

Change-Id: If28b7e9fc4fc0d6dc851e35007fd7614a9b497a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4558664
Auto-Submit: Joey Arhar <[email protected]>
Commit-Queue: Joey Arhar <[email protected]>
Reviewed-by: Robert Flack <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1160284}

[wpt-pr-bot]

The review process for this patch is being conducted in the Chromium project.

[BorisChiou]

Should we update cssTransitionsInterpolation::nonInterpolationExpectations instead?

[dholbert]

@josepharhar just checking in, is there anything blocking this at this point, or is this good to be merged?

(Maybe that'll happen automagically after something else happens; I'm not sure about the lifecycle for Chromium WPT merges. I do see that the linked chromium-review page ends with This CL has failed the run. Reason: [...] blink_wpt_tests failed [...]. Not sure if that's blocking this or not; it looks like that might be just showing Blink's prototype interpolation behavior which differs from the test's [legacy/non-prototype] expectations?)

[josepharhar]

I'm on it, I had to mess with the flag and do some rebaselining. I'll send it out for review in chromium today.

[dholbert]

@josepharhar hi! Checking in again -- do you think we can get this merged soon?

[josepharhar]

Sorry for being slow, the change caused a large number of changes in our testexpectations which got uneasy feedback in the code review. I just responded with a justification, hopefully it goes over well