include: Add Windows.UI.Composition.LinearEasingFunction definition.

include/windows.ui.composition.idl

@@ -63,6 +63,7 @@ namespace Windows.UI.Composition {
     interface ICubicBezierEasingFunction;
     interface IExpressionAnimation;
     interface IInsetClip;
+    interface ILinearEasingFunction;
     interface ISpriteVisual;
     interface ISpriteVisual2;
     interface IVisual;
@@ -86,6 +87,7 @@ namespace Windows.UI.Composition {
     runtimeclass CubicBezierEasingFunction;
     runtimeclass ExpressionAnimation;
     runtimeclass InsetClip;
+    runtimeclass LinearEasingFunction;
     runtimeclass KeyFrameAnimation;
     runtimeclass SpriteVisual;
     runtimeclass Visual;
@@ -382,6 +384,15 @@ namespace Windows.UI.Composition {
 
     [
         contract(Windows.Foundation.UniversalApiContract, 2.0),
+        exclusiveto(Windows.UI.Composition.LinearEasingFunction),
+        uuid(9400975a-c7a6-46b3-acf7-1a268a0a117d)
+    ]
+    interface ILinearEasingFunction : IInspectable
+    {
+    }
+
+    [
+        contract(Windows.Foundation.UniversalApiContract, 2.0),
         exclusiveto(Windows.UI.Composition.SpriteVisual),
         uuid(08e05581-1ad1-4f97-9757-402d76e4233b)
     ]
@@ -591,6 +602,16 @@ namespace Windows.UI.Composition {
         marshaling_behavior(agile),
         threading(both)
     ]
+    runtimeclass LinearEasingFunction : Windows.UI.Composition.CompositionEasingFunction
+    {
+        [default] interface Windows.UI.Composition.ILinearEasingFunction;
+    }
+
+    [
+        contract(Windows.Foundation.UniversalApiContract, 2.0),
+        marshaling_behavior(agile),
+        threading(both)
+    ]
     runtimeclass SpriteVisual : Windows.UI.Composition.ContainerVisual
     {
         [default] interface Windows.UI.Composition.ISpriteVisual;