src/vs/base/browser/globalMouseMoveMonitor.ts/standardMouseMoveMerger
export function standardMouseMoveMerger(lastEvent: IStandardMouseMoveEventData | null, currentEvent: MouseEvent): IStandardMouseMoveEventData {
	let ev = new StandardMouseEvent(currentEvent);
	ev.preventDefault();
	return {
		leftButton: ev.leftButton,
		buttons: ev.buttons,
		posx: ev.posx,
		posy: ev.posy
	};
}