Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/LocalAppContextSwitches.cs

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+// <copyright>
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+namespace System.ServiceModel
+{
+    using System;
+    using System.Runtime.CompilerServices;
+
+    // When adding a quirk, name it such that false is new behavior and true is old behavior.
+    // You are opting IN to old behavior. The new behavior is default.
+    // For example, we want to enable the functionality to explicitly add a connection close header
+    // in 4.6 and above. So we set DisableExplicitConnectionCloseHeader to true if running 4.5.2 or less.
+    internal static class LocalAppContextSwitches
+    {
+        private const string DisableExplicitConnectionCloseHeaderString = "Switch.System.ServiceModel.DisableExplicitConnectionCloseHeader";
+        private const string AllowUnsignedToHeaderString = "Switch.System.ServiceModel.AllowUnsignedToHeader";
+
+        private static int disableExplicitConnectionCloseHeader;
+        private static int allowUnsignedToHeader;
+
+        public static bool DisableExplicitConnectionCloseHeader
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return LocalAppContext.GetCachedSwitchValue(DisableExplicitConnectionCloseHeaderString, ref disableExplicitConnectionCloseHeader);
+            }
+        }
+
+        public static bool AllowUnsignedToHeader
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return LocalAppContext.GetCachedSwitchValue(AllowUnsignedToHeaderString, ref allowUnsignedToHeader);
+            }
+        }
+
+        public static void SetDefaultsLessOrEqual_452()
+        {
+            // Define the switches that should be true for 4.5.2 or less, false for 4.6+.
+            LocalAppContext.DefineSwitchDefault(DisableExplicitConnectionCloseHeaderString, true);
+        }
+    }
+}