Remove onscroll/onresize EventHandler supper from ViewportAPI

third_party/WebKit/Source/core/frame/VisualViewport.idl

 /*
  * Copyright (C) 2016 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 copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 22 matching lines @@
     [Measure] readonly attribute double scrollLeft;
     [Measure] readonly attribute double scrollTop;
 
     [Measure] readonly attribute double pageX;
     [Measure] readonly attribute double pageY;
 
     [Measure] readonly attribute double clientWidth;
     [Measure] readonly attribute double clientHeight;
 
     [Measure] readonly attribute double scale;
-
-    attribute EventHandler onresize;
-    attribute EventHandler onscroll;
 };