r260356 appears to use functions of NetworkSession that appear to be declared in a ENABLE(RESOURCE_LOAD_STATISTICS) block with no guard.
Created attachment 396997 [details] Patch
Comment on attachment 396997 [details] Patch r=me, looks like this code was moved from a Cocoa-specific file that was making this assumption without issue.
Committed r260391: <https://trac.webkit.org/changeset/260391> All reviewed patches have been landed. Closing bug and clearing flags on attachment 396997 [details].
<rdar://problem/62072250>