Definition
WebVTT: The Web Video Text Tracks Format defines VTTRegion
[Exposed=Window]
interface VTTRegion {
constructor();
attribute DOMString id;
attribute double width;
attribute unsigned long lines;
attribute double regionAnchorX;
attribute double regionAnchorY;
attribute double viewportAnchorX;
attribute double viewportAnchorY;
attribute ScrollSetting scroll;
};