[css-animations-2][scroll-animations-1] Avoid merging named timeline range keyframes which compute to the same offset

[flackr]

In css-animations-2 3. Keyframes step 6.4, two keyframes with the same keyframe offset, timing function and composite will be merged into the same keyframe. We may need to call out that keyframes which compute to the same offset but have different named timeline range offsets should not be merged just as we don't merge keyframes with different easing functions or composite values.

Merging such cases would end up dynamically merging different groups of keyframes depending on the specific layout which feels unnecessarily expensive to keep up to date and odd from a developer perspective that the keyframe count would vary dynamically based on layout.

[css-meeting-bot]

The CSS Working Group just discussed [css-animations-2][scroll-animations-1] Avoid merging named timeline range keyframes which compute to the same offset, and agreed to the following:

• RESOLVED: Merge keyframes if their *specified* offsets match, don't try to merge based on computed

The full IRC log of that discussion

<TabAtkins> flackr: this was already implied by an earlier issue
<TabAtkins> flackr: If two keyframes have same offset, don't merge unless they have identical specified value
<TabAtkins> flackr: (Not if their offsets compute to the same value)
<dbaron> previous issue was https://github.com//issues/8507 ?
<TabAtkins> RESOLVED: Merge keyframes if their *specified* offsets match, don't try to merge based on computed