Add UseCounters for Element.offset*

Source/core/dom/Element.idl

 /*
  * Copyright (C) 2006, 2007, 2009 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,
@@ skipping 78 matching lines @@
     [RuntimeEnabled=CSSOMSmoothScroll] void scrollBy(unrestricted double x, unrestricted double y);
     attribute unrestricted double scrollTop;
     attribute unrestricted double scrollLeft;
     readonly attribute long scrollWidth;
     readonly attribute long scrollHeight;
     readonly attribute long clientTop;
     readonly attribute long clientLeft;
     readonly attribute long clientWidth;
     readonly attribute long clientHeight;
     // http://dev.w3.org/csswg/cssom-view/#extensions-to-the-htmlelement-interface
-    // FIXME: offset* should be on HTMLElement.
-    [ImplementedAs=offsetParentForBindings, PerWorldBindings] readonly attribute Element? offsetParent;
-    readonly attribute long offsetTop;
-    readonly attribute long offsetLeft;
-    readonly attribute long offsetWidth;
-    readonly attribute long offsetHeight;
+    // FIXME: offset* should only be on HTMLElement.
+    [MeasureAs=ElementOffsetParent, ImplementedAs=offsetParentForBindings, PerWorldBindings] readonly attribute Element? offsetParent;
+    [MeasureAs=ElementOffsetTop] readonly attribute long offsetTop;
+    [MeasureAs=ElementOffsetLeft] readonly attribute long offsetLeft;
+    [MeasureAs=ElementOffsetWidth] readonly attribute long offsetWidth;
+    [MeasureAs=ElementOffsetHeight] readonly attribute long offsetHeight;
 
     // CSS Object Model (CSSOM)
     // http://dev.w3.org/csswg/cssom/#the-elementcssinlinestyle-interface
     // FIXME: style should be on HTMLElement and SVGElement.
     // FIXME: style should have [PutForwards=cssText].
     [SameObject, PerWorldBindings] readonly attribute CSSStyleDeclaration style;
 
     // HTML
     // https://html.spec.whatwg.org/#htmlelement
     // FIXME: dataset, focus() and blur() should be on HTMLElement.
@@ skipping 27 matching lines @@
     [RuntimeEnabled=Touch] attribute EventHandler ontouchcancel;
     [RuntimeEnabled=Touch] attribute EventHandler ontouchend;
     [RuntimeEnabled=Touch] attribute EventHandler ontouchmove;
     [RuntimeEnabled=Touch] attribute EventHandler ontouchstart;
     attribute EventHandler onwheel;
 };
 
 Element implements ParentNode;
 Element implements ChildNode;
 Element implements NonDocumentTypeChildNode;