If multiple processes share a temp directory, than webkitcorepy's autoinstaller is unsafe.
<rdar://problem/99574043>
Pull request: https://github.com/WebKit/WebKit/pull/4080
Committed 254210@main (e310ded33496): <https://commits.webkit.org/254210@main> Reviewed commits have been landed. Closing PR #4080 and removing active labels.
Committed 252432.354@safari-7614-branch (6865529f54c1): <https://commits.webkit.org/252432.354@safari-7614-branch> Reviewed commits have been landed. Closing PR #44 and removing active labels.