Fix bug that caused the stylesheet callback to be called before it is actually ready.
Fix bug that caused the stylesheet callback to be called before it is actually ready.

typekit/webfontloader,sapics/webfontloader,sapics/webfontloader,ramghaju/webfontloader,sapics/webfontloader,Monotype/webfontloader,ramghaju/webfontloader,ramghaju/webfontloader,Monotype/webfontloader,Monotype/webfontloader,typekit/webfontloader,typekit/webfontloader