Add UseCounters for non-standard WheelEvent.wheelDelta* attributes

Source/core/events/WheelEvent.idl

 /*
  * Copyright (C) 2006, 2007, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2013 Samsung Electronics. All rights reserved.
  *
  * 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.
  *
@@ skipping 15 matching lines @@
     // DeltaModeCode
     const unsigned long              DOM_DELTA_PIXEL = 0x00;
     const unsigned long              DOM_DELTA_LINE  = 0x01;
     const unsigned long              DOM_DELTA_PAGE  = 0x02;
 
     [InitializedByEventConstructor] readonly attribute double deltaX;
     [InitializedByEventConstructor] readonly attribute double deltaY;
     [InitializedByEventConstructor] readonly attribute double deltaZ;
     [InitializedByEventConstructor] readonly attribute unsigned long deltaMode;
 
-    // Non standard API.
-    [InitializedByEventConstructor] readonly attribute long wheelDeltaX;
-    [InitializedByEventConstructor] readonly attribute long wheelDeltaY;
-    readonly attribute long wheelDelta;
+    // Non-standard API.
+    [InitializedByEventConstructor, MeasureAs=WheelEventWheelDeltaX] readonly attribute long wheelDeltaX;
+    [InitializedByEventConstructor, MeasureAs=WheelEventWheelDeltaY] readonly attribute long wheelDeltaY;
+    [MeasureAs=WheelEventWheelDelta] readonly attribute long wheelDelta;
 
     // WebKit Extension
     [MeasureAs=PrefixedWheelEventDirectionInvertedFromDevice]
     readonly attribute boolean webkitDirectionInvertedFromDevice;
 
     [MeasureAs=PrefixedWheelEventInit]
     void initWebKitWheelEvent([Default=Undefined] optional long wheelDeltaX,
                               [Default=Undefined] optional long wheelDeltaY,
                               [Default=Undefined] optional Window view,
                               [Default=Undefined] optional long screenX,
                               [Default=Undefined] optional long screenY,
                               [Default=Undefined] optional long clientX,
                               [Default=Undefined] optional long clientY,
                               [Default=Undefined] optional boolean ctrlKey,
                               [Default=Undefined] optional boolean altKey,
                               [Default=Undefined] optional boolean shiftKey,
                               [Default=Undefined] optional boolean metaKey);
 };