WebKit should support transitions of CSS gradients. As a first pass, we should animate between gradients with the same type, and the same number of color stops.
In future, we could synthesize color stops to be able to animate between gradients with different numbers of stops.
I guess we could interpolate between radial and linear by increasing the radius towards infinity?
Hrm, this is harder than I thought. We actually need to animate background-image; -webkit-gradient is just a type of image.
It's even harder:
1. Ideally we need to handle transitions via FillLayers, so we deal with multiple backgrounds.
2. When we do this, we should make it so that we can cross-fade background images.
3. The CSS gradient info is not held in the RenderStyle structures. The StyleImage for a gradient is a StyleGeneratedImage, which points back to a CSSImageGeneratorValue, from which a Gradient is created on the fly for painting.
*** This bug has been marked as a duplicate of bug 21725 ***