DrawScrollingContentsOp: Accelerated Scrolling via Raster-Inducing Display Lists

The provided text describes DrawScrollingContentsOp, a specialized paint operation within Chromium’s rendering engine that enhances scrolling performance for non-composited content. By utilizing the RasterInducingScroll feature, this operation allows the compositor to manage scrolling tasks that were previously handled by the main thread. It functions by embedding a nested display list of scrollable content into a larger list, using a unique ElementId to track and apply scroll offsets during the rasterization phase. This mechanism avoids the need for expensive repaints on every scroll movement, significantly reducing memory overhead and processing lag. Ultimately, the technical documentation illustrates how Chromium achieves fluid, accelerated scrolling by intelligently rendering only the visible portions of large content areas.