Additional specifiction conformance updates

* Ensure animated keyframe values are in an array
* Move end keyframe values to start of the next keyframe

The only major failure that remains is some properties missing "a"
values. We will probably update the specification to allow a default
value for this at some point in the future, so leaving for now.

Change-Id: Ide22df0a239ec91c5fdb1683c06ed0d1db46b472
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/856856
Commit-Queue: Brandon Wilson <bwils@google.com>
Reviewed-by: Florin Malita <fmalita@google.com>
Reviewed-by: Jorge Betancourt <jmbetancourt@google.com>
2 files changed