Adjust isPlainObject test to run in an iframe.
Adjust isPlainObject test to run in an iframe.

praveen9102/Shazam,kpozin/jquery-nodom,diracdeltas/jquery,Karyotyper/jquery,npmcomponent/component-jquery,eburgos/jquery,mislav/jquery,fat/jquery,ilyakharlamov/jquery-xul,eburgos/jquery,dtjm/jquery,dtjm/jquery,diracdeltas/jquery,rwaldron/jquery,diracdeltas/jquery,chitranshi/jquery,roytoo/jquery,isaacs/jquery,jcutrell/jquery,praveen9102/Shazam,roytoo/jquery,jcutrell/jquery,scottjehl/jquery,jquery/jquery,eburgos/jquery,chitranshi/jquery,RubyLouvre/jquery,RubyLouvre/jquery,Karyotyper/jquery,ilyakharlamov/jquery-xul,demetr84/Jquery,jquery/jquery,jquery/jquery,gnarf/jquery,roytoo/jquery,kpozin/jquery-nodom,isaacs/jquery,sancao2/jquery,hoorayimhelping/jquery,fat/jquery,npmcomponent/component-jquery,demetr84/Jquery,Karyotyper/jquery,sancao2/jquery,quiaro/request-agent,mislav/jquery,hoorayimhelping/jquery,rwaldron/jquery,scottjehl/jquery,gnarf/jquery,sancao2/jquery