Imported Upstream version 4.3.2.467

Former-commit-id: 9c2cb47f45fa221e661ab616387c9cda183f283d

external/referencesource/System.Web/Util/HeapAllocHandle.cs

@@ -0,0 +1,26 @@
+//------------------------------------------------------------------------------
+// <copyright file="HeapAllocHandle.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.Util {
+    using System;
+    using System.Diagnostics.CodeAnalysis;
+    using Microsoft.Win32.SafeHandles;
+
+    internal class HeapAllocHandle : SafeHandleZeroOrMinusOneIsInvalid {
+        [SuppressMessage("Microsoft.Reliability", "CA2006:UseSafeHandleToEncapsulateNativeResources", Justification = @"This pointer is valid for the lifetime of the process; never needs to be released.")]
+        private static readonly IntPtr ProcessHeap = UnsafeNativeMethods.GetProcessHeap();
+
+        // Called by P/Invoke when returning SafeHandles
+        protected HeapAllocHandle()
+            : base(ownsHandle: true) {
+        }
+
+        // Do not provide a finalizer - SafeHandle's critical finalizer will call ReleaseHandle for you.
+        protected override bool ReleaseHandle() {
+            return UnsafeNativeMethods.HeapFree(ProcessHeap, 0, handle);
+        }
+    }
+}