Slimming Paint (a.k.a. Redesigning Painting and Compositing)

Slimming Paint is a Paint team project to re-implement the Blink<->cc picture recording API to work in terms of a global display list rather than a tree of cc::Layers (~aka GraphicsLayer in Blink terminology). It will result in a drastic simplification of the way that composited layers are represented in Blink and cc, which in turn will yield improved performance, correctness and flexibility.

To get a sense of the extent of this rewrite, one side-effect will be the deletion of the code in core/rendering/compositing/.

Phases

SlimmingPaintV1 - paint using display items (Status: launched in M45)

SlimmingPaintInvalidation - rewrite of paint invalidation using display items, property trees introduced in blink (Status: launched in M58)

SlimmingPaintV175 - uses property trees for painting in blink, introduces paint chunks, uses paint chunks for raster invalidation (Status: launched in M67)

BlinkGenPropertyTrees - sends a layer list instead of a tree, and generates final property trees in blink instead of re-generating them in cc (Status: launched in M75)

CompositeAfterPaint - compositing decisions made after paint.