Definition
CSSOM View Module defines VisualViewport
[Exposed=Window]
interface VisualViewport : EventTarget {
readonly attribute double offsetLeft;
readonly attribute double offsetTop;
readonly attribute double pageLeft;
readonly attribute double pageTop;
readonly attribute double width;
readonly attribute double height;
readonly attribute double scale;
attribute EventHandler onresize;
attribute EventHandler onscroll;
attribute EventHandler onscrollend;
};