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..4cd35d7168b9ded8f8933c9a69f4af1a40c29c49 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 long deltaX;

[do-not-use, 2013/08/16 09:57:16]

These should be "double", not "long". I'll fix this in the next iteration as
well.

[do-not-use, 2013/08/16 12:02:50]

Done.

+    [InitializedByEventConstructor] readonly attribute long deltaY;
+    // [InitializedByEventConstructor] readonly attribute long deltaZ;
     [InitializedByEventConstructor] readonly attribute unsigned long deltaMode;
 
+    // Non standard API.
+    [InitializedByEventConstructor, ImplementedAs=deltaX] readonly attribute long wheelDeltaX;

[arv (Not doing code reviews), 2013/08/15 14:05:44]

OK. I see, we use the same interface... this should also be deprecated when we
deprecate onmousewheel.

[do-not-use, 2013/08/16 12:02:50]

Right, I use the same interface because the interface name if the same as in the
standard and it is exposed to JavaScript already. We can deprecate (or measure
usage) of the non-standard API in a follow-up patch.

+    [InitializedByEventConstructor, ImplementedAs=deltaY] readonly attribute long wheelDeltaY;
     readonly attribute long wheelDelta;
 
     // WebKit Extension