Resolved pixel scaling ratio. Unless explicitly overridden by the
DoughnutChartView.PixelScalingRatio property, this one returns the default ratio enforced by device. High resolution devices will initialize this property to a higher value.
Target Platforms: Android 4.4+, iOS 8+
Development Environments: Visual Studio 2015+, Visual Studio for Mac Preview, Xamarin for Visual Studio 4.2+