Remove GarbageCollected support from the bindings

sky/engine/core/css/FontFace.idl

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 25 matching lines @@
     "loaded",
     "error"
 };
 
 [
     // FIXME: should be union type http://crbug.com/240176
     Constructor(DOMString family, DOMString source, optional Dictionary descriptors),
     Constructor(DOMString family, ArrayBuffer source, optional Dictionary descriptors),
     Constructor(DOMString family, ArrayBufferView source, optional Dictionary descriptors),
     ConstructorCallWith=ExecutionContext,
-    WillBeGarbageCollected,
 ] interface FontFace {
 
     [RaisesException=Setter, SetterCallWith=ExecutionContext] attribute DOMString family;
     [RaisesException=Setter, SetterCallWith=ExecutionContext] attribute DOMString style;
     [RaisesException=Setter, SetterCallWith=ExecutionContext] attribute DOMString weight;
     [RaisesException=Setter, SetterCallWith=ExecutionContext] attribute DOMString stretch;
     [RaisesException=Setter, SetterCallWith=ExecutionContext] attribute DOMString unicodeRange;
     [RaisesException=Setter, SetterCallWith=ExecutionContext] attribute DOMString variant;
     [RaisesException=Setter, SetterCallWith=ExecutionContext] attribute DOMString featureSettings;
 
     readonly attribute FontFaceLoadStatus status;
     [CallWith=ScriptState] readonly attribute Promise loaded;
 
     [CallWith=ScriptState] Promise load();
 };