CSS backgrounds and WebTransport congestion control

Chromium developers posted two intents to ship on blink-dev, covering CSS background computed values and a WebTransport congestion hint. Both changes move Chromium closer to other engines or to planned transport refinements.

Background layer count independence

Chrome plans to ship CSS background longhand computed-value layer independence as specified in Values 4 Appendix A. The behavior already matches Firefox and Safari. Authors obtain consistent layer counts in computed styles for multi-layer backgrounds across the major engines.

WebTransport congestion control

Chromium received LGTM to ship the WebTransport congestionControl hint. Both hint values will initially map to BBRv2, with later refinement expected. Applications gain an explicit signal for choosing congestion behavior on WebTransport sessions.