[css-compositing] test suite for grouping

All,

We recently created patches for WebKit, Blink and Firefox that implement
background blending [1].
In response to David's concerns, we started to create a test matrix to
determine where the rendering behavior is different between browsers:
http://mire.github.io/blending_samples/

Each square contains 2 background images: a partially transparent gradient
and a duck that has a blend mode attached to it.
(#*blendmodeduckfighting*<https://twitter.com/search?q=%23blendmodeduckfighting&src=hash>
)
Each test page consists of a table. Each row tests a different css
property. The first column shows your current browser's behavior. The other
columns point to chrome, safari and firefox.

We already found some differences and we're in the process of making a test
page with transitions and animations.
Does anyone have know what other CSS features we should test to determine
grouping behavior?

Rik


1:
https://dvcs.w3.org/hg/FXTF/rawfile/tip/compositing/index.html#background-blend-mode