Inline `relayPaintMetrics` function (#8954)
Inline `relayPaintMetrics` function (#8954)

This function was only used once. I missed it in review, but this should save us a few bytes.
BlancheXu/test,flybayer/next.js,JeromeFitz/next.js,BlancheXu/test,zeit/next.js,flybayer/next.js,flybayer/next.js,flybayer/next.js,zeit/next.js,BlancheXu/test,azukaru/next.js,JeromeFitz/next.js,azukaru/next.js,JeromeFitz/next.js,JeromeFitz/next.js,azukaru/next.js,zeit/next.js,azukaru/next.js