onLoading property

Stream<FontFaceSetLoadEvent> onLoading
@DocsEditable(), @DomName('FontFaceSet.onloading'), @Experimental()

Implementation 

@DomName('FontFaceSet.onloading')
@DocsEditable()
@Experimental() // untriaged
Stream<FontFaceSetLoadEvent> get onLoading => loadingEvent.forTarget(this);