Preserve none in computed relative colors without a conversion
Per discussion at w3c/csswg-drafts#10360,
there are a few test cases that incorrectly expect none to be
resolved to 0 in relative colors where no color space conversion was
needed. This CL updates both the test and the behavior in Blink.
Bug: 365818844
Change-Id: I14d6f83d792e4fb4e70171b833de308c66611fb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5905968
Reviewed-by: Fredrik Söderquist fs@opera.com
Commit-Queue: Kevin Babbitt kbabbitt@microsoft.com
Cr-Commit-Position: refs/heads/main@{#1368963}