fix: change #if defined(OS_MACOSX) to #if defined(OS_MAC) (#28102)

shell/browser/api/electron_api_browser_window.cc

@@ -372,7 +372,7 @@ void BrowserWindow::RemoveBrowserView(v8::Local<v8::Value> value) {
 void BrowserWindow::SetTopBrowserView(v8::Local<v8::Value> value,
                                       gin_helper::Arguments* args) {
   BaseWindow::SetTopBrowserView(value, args);
-#if defined(OS_MACOSX)
+#if defined(OS_MAC)
   UpdateDraggableRegions(draggable_regions_);
 #endif
 }