SKSvg - Fixed SVG not loaded when viewvport / viewbox not specified

source/SkiaSharp.Svg/SkiaSharp.Svg.Shared/SKSvg.cs

@@ -93,6 +93,15 @@ namespace SkiaSharp
 			{
 				ViewBox = ReadRectangle(viewBoxA.Value);
 			}
+			else
+			{
+				var widthA = svg.Attribute("width");
+				var heightA = svg.Attribute("height");
+				var width = ReadNumber(widthA);
+				var height = ReadNumber(heightA);
+				var size = new SKSize(width, height);
+				ViewBox = SKRect.Create(size);
+			}
 
 			if (CanvasSize.IsEmpty)
 			{