Chrome's CSS Scroll Snap Implementation: Blink and Compositor Deep Dive

The source provides an extensive technical explanation of the implementation of CSS Scroll Snap within the Google Chrome browser, specifically detailing how the feature is managed across the Blink rendering engine and the Chromium Compositor (CC). It begins by outlining the historical evolution of scroll snapping from early coordinate-based specifications to the modern element-based model, which uses properties like scroll-snap-type and scroll-snap-align. The text then describes the division of labor: Blink handles the interpretation of CSS and calculates precise snap coordinates (SnapContainerData), while the Compositor thread utilizes this data along with various SnapSelectionStrategy objects to manage smooth scroll animations, handle user input, and ensure correct snapping behavior (including managing the 50% proximity threshold and scroll-snap-stop priority). Finally, the document discusses future developments for the feature, such as the introduction of scroll snap events and potential fine-grained control for developers.