Expect call to wrapper

shell/platform/windows/flutter_window_unittests.cc

@@ -154,10 +154,13 @@ class TestFlutterWindowsView : public FlutterWindowsView {
  public:
   TestFlutterWindowsView(std::unique_ptr<WindowBindingHandler> window_binding)
       : FlutterWindowsView(std::move(window_binding)) {}
+  ~TestFlutterWindowsView() {}
 
   SpyKeyboardKeyHandler* key_event_handler;
   SpyTextInputPlugin* text_input_plugin;
 
+  MOCK_METHOD4(NotifyWinEventWrapper, void(DWORD, HWND, LONG, LONG));
+
  protected:
   std::unique_ptr<KeyboardHandlerBase> CreateKeyboardKeyHandler(
       flutter::BinaryMessenger* messenger,
@@ -406,10 +409,10 @@ TEST(FlutterWindowTest, InitialAccessibilityFeatures) {
 TEST(FlutterWindowTest, AlertNode) {
   std::unique_ptr<MockFlutterWindow> win32window =
       std::make_unique<MockFlutterWindow>();
-  ;
   ON_CALL(*win32window, GetPlatformWindow()).WillByDefault(Return(nullptr));
   AccessibilityRootNode* root_node = win32window->GetAccessibilityRootNode();
   TestFlutterWindowsView view(std::move(win32window));
+  EXPECT_CALL(view, NotifyWinEventWrapper(EVENT_SYSTEM_ALERT, nullptr, OBJID_CLIENT, AccessibilityRootNode::kAlertChildId)).Times(1);
   std::wstring message = L"Test alert";
   view.AnnounceAlert(message);
   IAccessible* alert = root_node->GetOrCreateAlert();

shell/platform/windows/flutter_windows_view.cc

@@ -661,6 +661,10 @@ void FlutterWindowsView::AnnounceAlert(const std::wstring& text) {
       binding_handler_->GetAccessibilityRootNode()->GetOrCreateAlert();
   alert->SetText(text);
   HWND hwnd = GetPlatformWindow();
+  NotifyWinEventWrapper(EVENT_SYSTEM_ALERT, hwnd, OBJID_CLIENT, AccessibilityRootNode::kAlertChildId);
+}
+
+void FlutterWindowsView::NotifyWinEventWrapper(DWORD event, HWND hwnd, LONG idObject, LONG idChild) {
   if (hwnd) {
     NotifyWinEvent(EVENT_SYSTEM_ALERT, hwnd, OBJID_CLIENT,
                    AccessibilityRootNode::kAlertChildId);

shell/platform/windows/flutter_windows_view.h

@@ -214,6 +214,8 @@ class FlutterWindowsView : public WindowBindingHandlerDelegate,
   virtual std::unique_ptr<TextInputPlugin> CreateTextInputPlugin(
       BinaryMessenger* messenger);
 
+  virtual void NotifyWinEventWrapper(DWORD event, HWND hwnd, LONG idObject, LONG idChild);
+
  private:
   // Struct holding the state of an individual pointer. The engine doesn't keep
   // track of which buttons have been pressed, so it's the embedding's