Improve test coverage of registered properties in paint worklets.

The most important use case for css-properties-values-api is having typed
(and possibly interpolated) custom properties in paint worklets.

So naturally, this is the *least* well tested use case in WPT. This CL
improves that by adding tests for most of the syntax types. The test works
as a kind of "ref" test, which compares the output of CSSStyleValue.parse
/parseAll with the value observed inside the worklet.

<transform-function> and <transform-list> are not supported yet, so they
will come later.

Interpolations should also be tested, but that belongs in a separate test.

Bug: 641877
Change-Id: I4bd310ecd61a2a8989df9c4a5c818cdc7c179b3a
Reviewed-on: https://chromium-review.googlesource.com/1209711
Commit-Queue: Anders Ruud <andruud@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589461}
2 files changed