FrameRateMonitor is always created since 263849@main, adapt build guards.
Pull request: https://github.com/WebKit/WebKit/pull/19218
Committed 269752@main (2e90c8258af2): <https://commits.webkit.org/269752@main> Reviewed commits have been landed. Closing PR #19218 and removing active labels.
<rdar://problem/117462776>