Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/rx/Rx/NET/Source/System.Reactive.Interfaces/Reactive/Subjects/ISubject.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+namespace System.Reactive.Subjects
+{
+    /// <summary>
+    /// Represents an object that is both an observable sequence as well as an observer.
+    /// </summary>
+    /// <typeparam name="T">The type of the elements processed by the subject.</typeparam>
+    public interface ISubject<T> : ISubject<T, T>
+    {
+    }
+}