Create a performance overlay that displays all available statistics
Source
PerformanceOverlay.allEnabled({ Key key, this.rasterizerThreshold: 0, this.checkerboardRasterCacheImages: false }) : optionsMask = ( 1 << PerformanceOverlayOption.displayRasterizerStatistics.index | 1 << PerformanceOverlayOption.visualizeRasterizerStatistics.index | 1 << PerformanceOverlayOption.displayEngineStatistics.index | 1 << PerformanceOverlayOption.visualizeEngineStatistics.index ), super(key: key);