PerformanceOverlay({Key key, int optionsMask: 0, int rasterizerThreshold: 0, bool checkerboardRasterCacheImages: false })

Create a performance overlay that only displays specific statistics. The mask is created by shifting 1 by the index of the specific StatisticOption to enable.

Source 

PerformanceOverlay({
  Key key,
  this.optionsMask: 0,
  this.rasterizerThreshold: 0,
  this.checkerboardRasterCacheImages: false
}) : super(key: key);