Reorder Challenge parameters.

Author: Tratcher

src/Microsoft.AspNet.Http.Core/Authentication/AuthenticationManager.cs

@@ -17,22 +17,27 @@ public abstract class AuthenticationManager
 
         public virtual void Challenge()
         {
-            Challenge(properties: null, authenticationScheme: null);
+            Challenge(authenticationScheme: null, properties: null);
         }
 
         public virtual void Challenge(AuthenticationProperties properties)
         {
-            Challenge(properties, "");
+            Challenge(authenticationScheme: null, properties: properties);
         }
 
         public virtual void Challenge(string authenticationScheme)
         {
-            Challenge(properties: null, authenticationScheme: authenticationScheme);
+            Challenge(authenticationScheme: authenticationScheme, properties: null);
         }
 
-        public abstract void Challenge(AuthenticationProperties properties, string authenticationScheme);
+        public abstract void Challenge(string authenticationScheme, AuthenticationProperties properties);
 
-        public abstract void SignIn(string authenticationScheme, ClaimsPrincipal principal, AuthenticationProperties properties = null);
+        public void SignIn(string authenticationScheme, ClaimsPrincipal principal)
+        {
+            SignIn(authenticationScheme, principal, properties: null);
+        }
+
+        public abstract void SignIn(string authenticationScheme, ClaimsPrincipal principal, AuthenticationProperties properties);
 
         public virtual void SignOut()
         {

src/Microsoft.AspNet.Http/Authentication/DefaultAuthenticationManager.cs

@@ -97,7 +97,7 @@ public override async Task<AuthenticationResult> AuthenticateAsync([NotNull] str
                 new AuthenticationDescription(authenticateContext.Description));
         }
 
-        public override void Challenge(AuthenticationProperties properties, string authenticationScheme)
+        public override void Challenge(string authenticationScheme, AuthenticationProperties properties)
         {
             HttpResponseFeature.StatusCode = 401;
             var handler = HttpAuthenticationFeature.Handler;