Update the FIXME around event handler attributes on body/frameset

Source/core/html/HTMLBodyElement.idl

 /*
  * Copyright (C) 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
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 interface HTMLBodyElement : HTMLElement {
     // obsolete members
     // https://html.spec.whatwg.org/#HTMLBodyElement-partial
     [Reflect, TreatNullAs=EmptyString] attribute DOMString text;
     [Reflect, TreatNullAs=EmptyString] attribute DOMString link;
     [Reflect, TreatNullAs=EmptyString] attribute DOMString vLink;
     [Reflect, TreatNullAs=EmptyString] attribute DOMString aLink;
     [Reflect, TreatNullAs=EmptyString] attribute DOMString bgColor;
     [Reflect] attribute DOMString background;
 
-    // FIXME: The spec requires special behavior for these event
-    // handler attributes but does not include them in the IDL:
-    // https://www.w3.org/Bugs/Public/show_bug.cgi?id=28166
+    // TODO(philipj): These event handler attributes should be inherited from
+    // HTMLElement (which implements GlobalEventHandlers), but have different
+    // behavior. See https://www.w3.org/Bugs/Public/show_bug.cgi?id=28166
     attribute EventHandler onblur;
     attribute EventHandler onerror;
     attribute EventHandler onfocus;
     attribute EventHandler onload;
     attribute EventHandler onresize;
     attribute EventHandler onscroll;
 
     // Non-standard APIs
     [RuntimeEnabled=OrientationEvent] attribute EventHandler onorientationchange;
 };
 
 HTMLBodyElement implements WindowEventHandlers;