Currently in WebProcess.cpp, the platform macros are used to enable periodic memory monitor of the memory pressure handler. It can be replaced with specific feature flag for better readability.
Created attachment 398983 [details] PATCH
ChangeLog entry in Source/WebKit/ChangeLog contains OOPS!.
Created attachment 398984 [details] PATCH
Committed r261462: <https://trac.webkit.org/changeset/261462> All reviewed patches have been landed. Closing bug and clearing flags on attachment 398984 [details].
<rdar://problem/63070718>