ENABLE_SHAREABLE_RESOURCE should be a PRIVATE build option. (I don't know what it is. How would users know what it is?) Looks like it was set to PUBLIC by mistake.
Created attachment 411076 [details] Patch
Committed r268388: <https://trac.webkit.org/changeset/268388> All reviewed patches have been landed. Closing bug and clearing flags on attachment 411076 [details].