Fix tests after exposing observer properties.
Fix tests after exposing observer properties.

kevinrodbe/fontfaceobserver,iksi/fontfaceobserver,kevinrodbe/fontfaceobserver,bramstein/fontfaceobserver,ttamminen/fontfaceobserver,bramstein/fontfaceobserver,ttamminen/fontfaceobserver,matuzo/fontfaceobserver,matuzo/fontfaceobserver,iksi/fontfaceobserver