Replace PlatformAbstractions with RuntimeInformation

Author: BrennanConroy

src/Microsoft.AspNetCore.Server.Kestrel/Infrastructure/Constants.cs

@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using Microsoft.Extensions.PlatformAbstractions;
+using System.Runtime.InteropServices;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Infrastructure
 {
@@ -28,32 +28,36 @@ internal class Constants
 
         private static int? GetECONNRESET()
         {
-            switch (PlatformServices.Default.Runtime.OperatingSystemPlatform)
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
-                case Platform.Windows:
-                    return -4077;
-                case Platform.Linux:
-                    return -104;
-                case Platform.Darwin:
-                    return -54;
-                default:
-                    return null;
+               return -4077;
             }
+            else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+            {
+                return -104;
+            }
+            else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+            {
+                return -54;
+            }
+            return null;
         }
 
         private static int? GetEADDRINUSE()
         {
-            switch (PlatformServices.Default.Runtime.OperatingSystemPlatform)
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+               return -4091;
+            }
+            else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+            {
+                return -98;
+            }
+            else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
             {
-                case Platform.Windows:
-                    return -4091;
-                case Platform.Linux:
-                    return -98;
-                case Platform.Darwin:
-                    return -48;
-                default:
-                    return null;
+                return -48;
             }
+            return null;
         }
     }
 }

src/Microsoft.AspNetCore.Server.Kestrel/Networking/PlatformApis.cs

@@ -3,27 +3,15 @@
 
 using System;
 using System.Runtime.InteropServices;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Networking
 {
     public static class PlatformApis
     {
         static PlatformApis()
         {
-#if NETSTANDARD1_3
             IsWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
             IsDarwin = RuntimeInformation.IsOSPlatform(OSPlatform.OSX);
-#else
-            var p = (int)Environment.OSVersion.Platform;
-            IsWindows = (p != 4) && (p != 6) && (p != 128);
-
-            if (!IsWindows)
-            {
-                // When running on Mono in Darwin OSVersion doesn't return Darwin. It returns Unix instead.
-                IsDarwin = PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Darwin;    
-            }
-#endif
         }
 
         public static bool IsWindows { get; }

src/Microsoft.AspNetCore.Server.Kestrel/project.json

@@ -14,11 +14,11 @@
   "dependencies": {
     "System.Buffers": "4.0.0-*",
     "System.Numerics.Vectors": "4.1.1-*",
+    "System.Runtime.InteropServices.RuntimeInformation": "4.0.0-*",
     "System.Threading.Tasks.Extensions": "4.0.0-*",
     "Libuv": "1.9.0-*",
     "Microsoft.AspNetCore.Hosting": "1.0.0-*",
-    "Microsoft.Extensions.Logging.Abstractions": "1.0.0-*",
-    "Microsoft.Extensions.PlatformAbstractions": "1.0.0-*"
+    "Microsoft.Extensions.Logging.Abstractions": "1.0.0-*"
   },
   "frameworks": {
     "net451": {