-Marked SerializationBinder as obsolete

Src/Newtonsoft.Json/Serialization/DefaultSerializationBinder.cs

@@ -35,7 +35,11 @@ namespace Newtonsoft.Json.Serialization
     /// <summary>
     /// The default serialization binder used when resolving and loading classes from type names.
     /// </summary>
-    public class DefaultSerializationBinder : SerializationBinder, ISerializationBinder
+    public class DefaultSerializationBinder :
+#pragma warning disable CS0618 // Type or member is obsolete
+        SerializationBinder,
+#pragma warning restore CS0618 // Type or member is obsolete
+        ISerializationBinder
     {
         internal static readonly DefaultSerializationBinder Instance = new DefaultSerializationBinder();
 

Src/Newtonsoft.Json/Serialization/SerializationBinderAdapter.cs

@@ -30,12 +30,16 @@ namespace Newtonsoft.Json.Serialization
 {
     internal class SerializationBinderAdapter : ISerializationBinder
     {
+#pragma warning disable 618
         public readonly SerializationBinder SerializationBinder;
+#pragma warning restore 618
 
+#pragma warning disable 618
         public SerializationBinderAdapter(SerializationBinder serializationBinder)
         {
             SerializationBinder = serializationBinder;
         }
+#pragma warning restore 618
 
         public Type BindToType(string assemblyName, string typeName)
         {

Src/Newtonsoft.Json/SerializationBinder.cs

@@ -8,6 +8,7 @@ namespace Newtonsoft.Json
     /// <summary>
     /// Allows users to control class loading and mandate what class to load.
     /// </summary>
+    [Obsolete("SerializationBinder is obsolete. Use ISerializationBinder instead.")]
     public abstract class SerializationBinder
     {
         /// <summary>