Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/Statements/Persist.cs

@@ -0,0 +1,47 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.Activities.Statements
+{
+    using System;
+    using System.Activities;
+    using System.Collections.Generic;
+
+    public sealed class Persist : NativeActivity
+    {
+        static BookmarkCallback onPersistCompleteCallback;
+
+        protected override void CacheMetadata(NativeActivityMetadata metadata)
+        {
+        }
+
+        protected override bool CanInduceIdle
+        {
+            get
+            {
+                return true;
+            }
+        }
+
+        protected override void Execute(NativeActivityContext context)
+        {
+            if (context.IsInNoPersistScope)
+            {
+                throw FxTrace.Exception.AsError(new InvalidOperationException(SR.CannotPersistInsideNoPersist));
+            }
+
+            if (onPersistCompleteCallback == null)
+            {
+                onPersistCompleteCallback = new BookmarkCallback(OnPersistComplete);
+            }
+
+            context.RequestPersist(onPersistCompleteCallback);
+        }
+
+        static void OnPersistComplete(NativeActivityContext context, Bookmark bookmark, object value)
+        {
+            // No-op.  This is here to keep the activity from completing.
+        }
+    }
+}