Make MathExtras.h thread safe.

        * kjs/math_object.cpp:
        (KJS::mathProtoFuncRandom): If threading is enabled, rely on initializeThreading to call
        wtf_random_init().

        * wtf/Threading.h:
        * wtf/ThreadingGtk.cpp:
        (WTF::initializeThreading):
        * wtf/ThreadingNone.cpp:
        (WTF::initializeThreading):
        * wtf/ThreadingPthreads.cpp:
        (WTF::initializeThreading):
        * wtf/ThreadingWin.cpp:
        (WTF::initializeThreading):
        Call wtf_random_init(); made the function non-inline to avoid having to include too many
        headers in Threading.h.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@31560 268f45cc-cd09-0410-ab3c-d52691b4dbfc