Create movementX/Y on MouseEvent

Source/web/WebInputEventConversion.cpp

Index: Source/web/WebInputEventConversion.cpp
diff --git a/Source/web/WebInputEventConversion.cpp b/Source/web/WebInputEventConversion.cpp
index 24dd9025a0754c8e7af417db6c05abbccca1f443..4a2ed1acdd795d95c3e8b8957a256157e22e7fcf 100644
--- a/Source/web/WebInputEventConversion.cpp
+++ b/Source/web/WebInputEventConversion.cpp
@@ -542,8 +542,8 @@ WebMouseEventBuilder::WebMouseEventBuilder(const Widget* widget, const WebCore::
         }
     } else
         button = WebMouseEvent::ButtonNone;
-    movementX = event.webkitMovementX();
-    movementY = event.webkitMovementY();
+    movementX = event.movementX();
+    movementY = event.movementY();
     clickCount = event.detail();
 }