Added more Rendering and GraphicsDeviceTypes; Disabled ping request count in Synchronize

UIX.Skia/Microsoft/Iris/Application.cs

@@ -467,6 +467,7 @@ namespace Microsoft.Iris
                     graphicsType = GraphicsDeviceType.Direct3D9;
                     break;
                 default:
+                    graphicsType = GraphicsDeviceType.Unknown;
                     throw new ArgumentException(InvariantString.Format("Unknown rendering type {0}", type));
             }
             if (type == RenderingType.Default && !s_session.IsGraphicsDeviceRecommended(graphicsType) || !s_session.IsGraphicsDeviceAvailable(graphicsType))

UIX.Skia/Microsoft/Iris/RenderingType.cs

@@ -10,6 +10,8 @@ namespace Microsoft.Iris
     {
         GDI,
         DX9,
-        Default,
+        Skia,
+
+        Default = -1,
     }
 }