Bug 12885 added absoluteOutlineBox(), which was later renamed to absoluteOutlineBounds(). The name gives little indication about how this differs from absoluteClippedOverflowRect(), so we should really come up with some better names. absoluteOutlineBounds() is the border bounding box inflated by shadow and outlines, whereas absoluteClippedOverflowRect() computes an accurate outline.
In Webkit Github mirror, there are still two instances of absoluteOutlineBounds() in following files: https://github.com/WebKit/WebKit/blob/e4e4bba1f291d4773b907199bb5e6976d14c223d/Source/WebCore/html/HTMLAreaElement.cpp#L111 https://github.com/WebKit/WebKit/blob/500b3dbc7c61814787e117e9e724f990f9fa2ec2/Source/WebCore/rendering/RenderObject.h#L765 Is something this renaming required or it is now OK? Thanks!