The submission interface used by cc to hand the frame to viz.

The packaged frame (passes + quads + metadata) submitted to the display compositor.

builds render passes and quads to describe what to draw this frame.

Schedules raster of picture tiles (Skia) into GPU resources as needed before draw.

Impl‑side layer objects that reference property‑tree nodes and emit draw quads from recorded paint (tiles).

(TransformTree / ClipTree / EffectTree / ScrollTree) with nodes cc::TransformNode / ClipNode / EffectNode / ScrollNode — The impl‑side property‑tree state that positions, clips, blends, and scrolls content each frame.

The compositor‑thread twin that owns the active/pending trees, runs impl‑side animations/scroll, and prepares draw. Implements cc::InputHandler for threaded scrolling/pinch.

Packages updated layers/property trees; kicks a commit to the compositor thread (via the proxy).

Bridges Blink’s paint property trees into cc property trees: creates/updates cc TransformNode, ClipNode, EffectNode, and ScrollNode (including inner/outer viewport scroll nodes).

Decides what needs to be composited and prepares the main‑thread representation to feed cc (layers if needed, scrollbar compositing, etc.).