Avoid unnecessary tree traversals in Page::setMemoryCacheClientCallsEnabled().
Pull request: https://github.com/WebKit/WebKit/pull/11637
Committed 261797@main (61fadadf20f5): <https://commits.webkit.org/261797@main> Reviewed commits have been landed. Closing PR #11637 and removing active labels.
<rdar://problem/106864021>