using internal Clamp method

Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs

@@ -209,23 +209,8 @@ namespace Xamarin.Forms.Platform.iOS
 			{
 				var positionOnScroll = Controller.GetScrollPositionForElement(e.Element as VisualElement, e.Position);
 
-				if (positionOnScroll.X < 0)
-				{
-					positionOnScroll.X = 0;
-				}
-				else if (positionOnScroll.X > ContentSize.Width - Bounds.Size.Width)
-				{
-					positionOnScroll.X = ContentSize.Width - Bounds.Size.Width;
-				}
-
-				if (positionOnScroll.Y < 0)
-				{
-					positionOnScroll.Y = 0;
-				}
-				else if (positionOnScroll.Y > ContentSize.Height - Bounds.Size.Height)
-				{
-					positionOnScroll.Y = ContentSize.Height - Bounds.Size.Height;
-				}
+				positionOnScroll.X = positionOnScroll.X.Clamp(0, ContentSize.Width - Bounds.Size.Width);
+				positionOnScroll.Y = positionOnScroll.Y.Clamp(0, ContentSize.Height - Bounds.Size.Height);
 
 				switch (ScrollView.Orientation)
 				{