this change adds RejectConnectionDart and supports cl/467032081.

PiperOrigin-RevId: 469757197

connections/clients/windows/dart/core_adapter_dart.cc

@@ -542,6 +542,25 @@ void AcceptConnectionDart(Core *pCore, const char *endpoint_id,
   finished.Await();
 }
 
+void RejectConnectionDart(Core *pCore, const char *endpoint_id,
+                          Dart_Port dart_port) {
+  if (!pCore) {
+    PostResult(dart_port, Status::Value::kError);
+    return;
+  }
+
+  port = dart_port;
+
+  ResultCallbackW callback;
+  SetResultCallback(callback, dart_port);
+
+  CountDownLatch finished(1);
+  adapter_finished = &finished;
+
+  RejectConnection(pCore, endpoint_id, callback);
+
+  finished.Await();
+}
 void DisconnectFromEndpointDart(Core *pCore, char *endpoint_id,
                                 Dart_Port dart_port) {
   if (!pCore) {

connections/clients/windows/dart/core_adapter_dart.h

@@ -259,6 +259,10 @@ DLL_API void __stdcall AcceptConnectionDart(Core *pCore,
                                             PayloadListenerDart listener_dart,
                                             Dart_Port result_cb);
 
+DLL_API void __stdcall RejectConnectionDart(Core *pCore,
+                                            const char *endpoint_id,
+                                            Dart_Port result_cb);
+
 // Disconnects from a remote endpoint. {@link Payload}s can no longer be sent
 // to or received from the endpoint after this method is called.
 // endpoint_id - The identifier for the remote endpoint to disconnect from.

connections/clients/windows/listeners_w.h

@@ -117,7 +117,6 @@ struct DLL_API ConnectionResponseInfoW {
 struct DLL_API PayloadProgressInfoW {
   PayloadId payload_id = 0;
   enum class Status {
-    kUnspecified = 0,
     kSuccess,
     kFailure,
     kInProgress,