This technical deep dive clarifies the separation of duties between Blink and the Chrome compositor (cc) regarding property tree construction. The text explains that Blink converts its own paint property trees into cc-specific property trees on the main thread using the PaintArtifactCompositor. Consequently, the subsequent "blocking commit" phase on the compositor thread does not perform any data conversion; it simply synchronizes or copies the already-processed cc property trees. The sources emphasize that the compositor thread never interacts with Blink’s internal node types, as the semantic translation is finalized before the commit begins. This architecture ensures that complex mapping logic, such as handling scroll offsets and sticky positioning, is handled by Blink rather than the compositor. Finally, the documentation provides a "proof by code" to dispel the misconception that tree conversion occurs during the cross-thread synchronization step.