browser runtime platform is much simpler.

src/Web/Avalonia.Web/BrowserRuntimePlatform.cs

@@ -11,62 +11,14 @@ internal class BrowserRuntimePlatform : StandardRuntimePlatform
 {
     private static readonly Lazy<RuntimePlatformInfo> Info = new(() =>
     {
-        OperatingSystemType os;
-
-        bool isBrowserMobile = false;
-
-        if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
-            os = OperatingSystemType.OSX;
-        else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
-            os = OperatingSystemType.Linux;
-        else if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
-            os = OperatingSystemType.WinNT;
-        else if (RuntimeInformation.IsOSPlatform(OSPlatform.Create("Android")))
-            os = OperatingSystemType.Android;
-        else if (RuntimeInformation.IsOSPlatform(OSPlatform.Create("iOS")))
-            os = OperatingSystemType.iOS;
-        else if (RuntimeInformation.IsOSPlatform(OSPlatform.Create("Browser")))
-        {
-            os = OperatingSystemType.Browser;
-            isBrowserMobile = AvaloniaModule.IsMobile();
-        }
-        else
-            throw new Exception("Unknown OS platform " + RuntimeInformation.OSDescription);
-
-        // Source: https://github.com/dotnet/runtime/blob/main/src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs
-        var isCoreClr = Environment.Version.Major >= 5 ||
-                        RuntimeInformation.FrameworkDescription.StartsWith(".NET Core",
-                            StringComparison.OrdinalIgnoreCase);
-        var isMonoRuntime = Type.GetType("Mono.Runtime") != null;
-        var isFramework = !isCoreClr &&
-                          RuntimeInformation.FrameworkDescription.StartsWith(".NET Framework",
-                              StringComparison.OrdinalIgnoreCase);
-
         var result = new RuntimePlatformInfo
         {
-            IsCoreClr = isCoreClr,
-            IsDotNetFramework = isFramework,
-            IsMono = isMonoRuntime,
-            IsDesktop = os is OperatingSystemType.Linux or OperatingSystemType.OSX or OperatingSystemType.WinNT,
-            IsMobile = os is OperatingSystemType.Android or OperatingSystemType.iOS,
-            IsUnix = os is OperatingSystemType.Linux or OperatingSystemType.OSX or OperatingSystemType.Android,
-            IsBrowser = os == OperatingSystemType.Browser,
-            OperatingSystem = os,
+            IsCoreClr = true, // WASM browser is always CoreCLR
+            IsBrowser = true, // BrowserRuntimePlatform only runs on Browser.
+            OperatingSystem = OperatingSystemType.Browser,
+            IsMobile = AvaloniaModule.IsMobile()
         };
-
-        if (result.IsBrowser)
-        {
-            if (isBrowserMobile)
-            {
-                result.IsMobile = true;
-            }
-            else
-            {
-                result.IsDesktop = true;
-            }
-        }
-
-
+        
         return result;
     });