Thetype exposes the following members.
Called when an external drag event enters the browser window.
Called whenever draggable regions for the browser window change. These can be specified using the '-webkit-app-region: drag/no-drag' CSS-property. If draggable regions are never defined in a document this method will also never be called. If the last draggable region is removed from a document this method will be called with an empty IList.