Undo CSSTransitionDiscrete interpolation test changes

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:
https://github.com/web-platform-tests/wpt/issues/39871

CSSTransitionDiscrete opt in syntax:
https://github.com/w3c/csswg-drafts/issues/8857

Change-Id: If28b7e9fc4fc0d6dc851e35007fd7614a9b497a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4558664
Auto-Submit: Joey Arhar <jarhar@chromium.org>
Commit-Queue: Joey Arhar <jarhar@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1160284}
diff --git a/css/css-fonts/discrete-no-interpolation.html b/css/css-fonts/discrete-no-interpolation.html
index 1888670..28760f6 100644
--- a/css/css-fonts/discrete-no-interpolation.html
+++ b/css/css-fonts/discrete-no-interpolation.html
@@ -10,8 +10,8 @@
 <script>
   test_no_interpolation({
     property: 'font-family',
-    from: 'initial',
-    to: 'c'
+    from: 'serif',
+    to: 'monospace'
   });
 
   test_no_interpolation({
diff --git a/css/support/interpolation-testcommon.js b/css/support/interpolation-testcommon.js
index 2ee00e4..ce180ff 100644
--- a/css/support/interpolation-testcommon.js
+++ b/css/support/interpolation-testcommon.js
@@ -56,7 +56,7 @@
       target.style.setProperty(property, isNeutralKeyframe(from) ? '' : from);
     },
     nonInterpolationExpectations: function(from, to) {
-      return expectFlip(from, to, 0.5);
+      return expectFlip(from, to, -Infinity);
     },
     notAnimatableExpectations: function(from, to, underlying) {
       return expectFlip(from, to, -Infinity);