Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/Tracking/WorkflowInstanceQuery.cs

@@ -0,0 +1,38 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.Activities.Tracking
+{
+    using System.Collections.ObjectModel;
+
+    public class WorkflowInstanceQuery : TrackingQuery
+    {
+        Collection<string> states;
+
+        public WorkflowInstanceQuery()
+        {
+        }
+
+        public Collection<string> States
+        {
+            get
+            {
+                if (this.states == null)
+                {
+                    this.states = new Collection<string>();
+                }
+                return this.states;
+            }
+        }
+
+        internal bool HasStates
+        {
+            get
+            {
+                return this.states != null && this.states.Count > 0;
+            }
+        }
+
+    }
+}