Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/Channels/IMessageSource.cs

@@ -0,0 +1,25 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace System.ServiceModel.Channels
+{
+    using System.Threading;
+
+    enum AsyncReceiveResult
+    {
+        Completed,
+        Pending,
+    }
+
+    interface IMessageSource
+    {
+        AsyncReceiveResult BeginReceive(TimeSpan timeout, WaitCallback callback, object state);
+        Message EndReceive();
+        Message Receive(TimeSpan timeout);
+
+        AsyncReceiveResult BeginWaitForMessage(TimeSpan timeout, WaitCallback callback, object state);
+        bool EndWaitForMessage();
+        bool WaitForMessage(TimeSpan timeout);
+    }
+}