Add support for DOM Level 3 WheelEvent

Source/core/dom/WheelEvent.idl

Index: Source/core/dom/WheelEvent.idl
diff --git a/Source/core/dom/WheelEvent.idl b/Source/core/dom/WheelEvent.idl
index 9dc0e4a49a26f17bb8196cd986c8b42a5016c544..8ee63ae3056fc23d8b1a04324d877e5916ede6bd 100644
--- a/Source/core/dom/WheelEvent.idl
+++ b/Source/core/dom/WheelEvent.idl
@@ -1,6 +1,7 @@
 /*
  * 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
@@ -18,17 +19,23 @@
  * Boston, MA 02110-1301, USA.
  */
 
+// Introduced in DOM Level 3:
 [
     ConstructorTemplate=Event
 ] 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;
 
-    [InitializedByEventConstructor] readonly attribute long wheelDeltaX;
-    [InitializedByEventConstructor] readonly attribute long wheelDeltaY;
+    [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;
 
     // WebKit Extension