Move CookieSecureOption / SecurePolicy to Http.Abstractions

src/Microsoft.AspNetCore.Http.Abstractions/CookieSecurePolicy.cs

@@ -0,0 +1,34 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace Microsoft.AspNetCore.Http
+{
+    /// <summary>
+    /// Determines how cookie security properties are set.
+    /// </summary>
+    public enum CookieSecurePolicy
+    {
+        /// <summary>
+        /// If the URI that provides the cookie is HTTPS, then the cookie will only be returned to the server on 
+        /// subsequent HTTPS requests. Otherwise if the URI that provides the cookie is HTTP, then the cookie will 
+        /// be returned to the server on all HTTP and HTTPS requests. This is the default value because it ensures
+        /// HTTPS for all authenticated requests on deployed servers, and also supports HTTP for localhost development 
+        /// and for servers that do not have HTTPS support.
+        /// </summary>
+        SameAsRequest,
+
+        /// <summary>
+        /// Secure is always marked true. Use this value when your login page and all subsequent pages
+        /// requiring the authenticated identity are HTTPS. Local development will also need to be done with HTTPS urls.
+        /// </summary>
+        Always,
+
+        /// <summary>
+        /// Secure is not marked true. Use this value when your login page is HTTPS, but other pages
+        /// on the site which are HTTP also require authentication information. This setting is not recommended because
+        /// the authentication information provided with an HTTP request may be observed and used by other computers
+        /// on your local network or wireless connection.
+        /// </summary>
+        None,
+    }
+}