Tried to fix the Yosemite build.

* wtf/Threading.cpp:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@174813 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reverted incorrect build fix attempt.

* wtf/Threading.cpp:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@174814 268f45cc-cd09-0410-ab3c-d52691b4dbfc