Imported Upstream version 6.6.0.89

Former-commit-id: b39a328747c2f3414dc52e009fb6f0aa80ca2492

external/illinker-test-assets/wasm/BlazingPizza.Client/JSRuntimeExtensions.cs

@@ -0,0 +1,13 @@
+using Microsoft.JSInterop;
+using System.Threading.Tasks;
+
+namespace BlazingPizza.Client
+{
+    public static class JSRuntimeExtensions
+    {
+        public static Task<bool> Confirm(this IJSRuntime jsRuntime, string message)
+        {
+            return jsRuntime.InvokeAsync<bool>("confirm", message);
+        }
+    }
+}