Fix CSSSelector copy constructor memory leak (the ref count is never 0)
rdar://108836283
Pull request: https://github.com/WebKit/WebKit/pull/13570
Committed 263859@main (28bb70d0289c): <https://commits.webkit.org/263859@main> Reviewed commits have been landed. Closing PR #13570 and removing active labels.
Committed 259548.753@safari-7615-branch (08cf44bc2869): <https://commits.webkit.org/259548.753@safari-7615-branch> Reviewed commits have been landed. Closing PR #592 and removing active labels.