Add support for DOM Level 3 WheelEvent

Source/core/dom/WheelEvent.h

Index: Source/core/dom/WheelEvent.h
diff --git a/Source/core/dom/WheelEvent.h b/Source/core/dom/WheelEvent.h
index ba17ab4ad2432fd22dcc01ebb32b281692cc6be6..e955b7300e3d176f4436582c583cc13ce4a67302 100644
--- a/Source/core/dom/WheelEvent.h
+++ b/Source/core/dom/WheelEvent.h
@@ -35,8 +35,8 @@ class PlatformWheelEvent;
 struct WheelEventInit : public MouseEventInit {
     WheelEventInit();
 
-    int wheelDeltaX;
-    int wheelDeltaY;
+    int deltaX;
+    int deltaY;
     unsigned deltaMode;
 };
 
@@ -78,8 +78,8 @@ public:
         bool ctrlKey, bool altKey, bool shiftKey, bool metaKey);
 
     int wheelDelta() const { return m_wheelDelta.y() ? m_wheelDelta.y() : m_wheelDelta.x(); }
-    int wheelDeltaX() const { return m_wheelDelta.x(); }
-    int wheelDeltaY() const { return m_wheelDelta.y(); }
+    int deltaX() const { return m_wheelDelta.x(); }
+    int deltaY() const { return m_wheelDelta.y(); }
     int rawDeltaX() const { return m_rawDelta.x(); }
     int rawDeltaY() const { return m_rawDelta.y(); }
     unsigned deltaMode() const { return m_deltaMode; }