computedStyle method
Implementation
CSSRenderStyle? computedStyle(String? pseudoElementSpecifier) {
// Do not trigger recalculateStyle() here. Callers (e.g., getComputedStyle)
// should first invoke Document.updateStyleIfNeeded(), which flushes pending
// stylesheet or inline changes. Re-entering recalc from here can clobber
// in-flight animation values (e.g., background-position) by re-expanding
// shorthands and resetting longhands to initial values.
// Also, permit access even before a render box is attached so computed
// properties like backgroundPosition can be observed during animation.
return renderStyle as CSSRenderStyle;
}