Merge pull request #180 from Unity-Technologies/finnif-patch-1

Update color_filter.cs

Author: zhuxingwei

com.unity.uiwidgets/Runtime/widgets/color_filter.cs

@@ -5,7 +5,7 @@
 namespace Unity.UIWidgets.widgets {
 
         public class ColorFiltered : SingleChildRenderObjectWidget {
-            protected ColorFiltered(
+            public ColorFiltered(
                 ColorFilter colorFilter = null, 
                 Widget child = null, 
                 Key key = null)
@@ -57,4 +57,4 @@ public override void paint(PaintingContext context, Offset offset) {
         }
 
 
-}
+}