The area on the top od the editor (containing the editor title - e.g. form name) and the area under it (containing the "Messages" title) are draggable, but instead of being dragged somewhere, they generate an error:

Unable to complete your request. The following exception occurred: Exception caught: Unattached drop target. You must call DragController#unregisterDropController for all drop targets not attached to the DOM.

This is currently not relevant for Firefox, beause the dragging functionality is blocked by UF-431.