This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
data property is a list of data usage statistics chunk. Each chunk is a
MozNetworkStatsData providing the total amount a bytes received and send during a given amount of time (this amount of time is accessible through the
var data = instanceOfMozNetworkStats.data;
Not part of any specification.