Updated to Chrome 45 (2454) moved from SVN to git.

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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
-// Introduced in DOM Level 3:
+// https://w3c.github.io/uievents/#interface-WheelEvent
+
 [
-    EventConstructor,
+    Constructor(DOMString type, optional WheelEventInit eventInitDict),
 ] interface WheelEvent : MouseEvent {
     // DeltaModeCode
-    const unsigned long              DOM_DELTA_PIXEL = 0x00;
-    const unsigned long              DOM_DELTA_LINE  = 0x01;
-    const unsigned long              DOM_DELTA_PAGE  = 0x02;
+    const unsigned long DOM_DELTA_PIXEL = 0x00;
+    const unsigned long DOM_DELTA_LINE = 0x01;
+    const unsigned long DOM_DELTA_PAGE = 0x02;
+    readonly attribute double deltaX;
+    readonly attribute double deltaY;
+    readonly attribute double deltaZ;
+    readonly attribute unsigned long deltaMode;
 
-    [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, MeasureAs=WheelEventWheelDeltaX] readonly attribute long wheelDeltaX;
-    [InitializedByEventConstructor, MeasureAs=WheelEventWheelDeltaY] readonly attribute long wheelDeltaY;
+    // Non-standard APIs
+    [MeasureAs=WheelEventWheelDeltaX] readonly attribute long wheelDeltaX;
+    [MeasureAs=WheelEventWheelDeltaY] readonly attribute long wheelDeltaY;
     [MeasureAs=WheelEventWheelDelta] readonly attribute long wheelDelta;
 };