Remove lots of machinery related to inline event handlers.

sky/engine/core/css/FontFaceSet.idl

Index: sky/engine/core/css/FontFaceSet.idl
diff --git a/sky/engine/core/css/FontFaceSet.idl b/sky/engine/core/css/FontFaceSet.idl
index 03f9058dfc85e768cbf836b08b80c86d717bf6cd..c88d24f6407d4dfed1736dd6cf9ac9db5a671938 100644
--- a/sky/engine/core/css/FontFaceSet.idl
+++ b/sky/engine/core/css/FontFaceSet.idl
@@ -36,10 +36,6 @@ enum FontFaceSetLoadStatus { "loading", "loaded" };
     NoInterfaceObject,
 ] interface FontFaceSet : EventTarget {
 
-    attribute EventHandler onloading;
-    attribute EventHandler onloadingdone;
-    attribute EventHandler onloadingerror;
-
     [RaisesException] boolean check(DOMString font, optional DOMString text = null);
     [CallWith=ScriptState] Promise load(DOMString font, optional DOMString text = null);
     [MeasureAs=FontFaceSetReady, CallWith=ScriptState] Promise ready();