[Extensions Bindings] Introduce a supportsLazyListeners property

extensions/browser/event_router.cc

Index: extensions/browser/event_router.cc
diff --git a/extensions/browser/event_router.cc b/extensions/browser/event_router.cc
index 4cab317e42e3bae5f27dc5b812020fe7c8ccb963..6013cfefad9e4d8434b4bbbe49e2aff4e3306d4d 100644
--- a/extensions/browser/event_router.cc
+++ b/extensions/browser/event_router.cc
@@ -6,6 +6,7 @@
 
 #include <stddef.h>
 
+#include <algorithm>
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
@@ -405,6 +406,16 @@ void EventRouter::ClearRegisteredEventsForTest(
                       RegisteredEventType::kServiceWorker);
 }
 
+bool EventRouter::HasLazyEventListenerForTesting(
+    const std::string& event_name) {
+  const EventListenerMap::ListenerList& listeners =
+      listeners_.GetEventListenersByName(event_name);
+  return std::any_of(listeners.begin(), listeners.end(),
+                     [](const std::unique_ptr<EventListener>& listener) {
+                       return listener->IsLazy();
+                     });
+}
+
 void EventRouter::RemoveFilterFromEvent(const std::string& event_name,
                                         const std::string& extension_id,
                                         const DictionaryValue* filter) {