Enumerate the return value of dispatchEvent so it is clear.

third_party/WebKit/Source/modules/notifications/Notification.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 100 matching lines @@
     const AtomicString& interfaceName() const override;
 
     // ActiveDOMObject interface.
     void stop() override;
     bool hasPendingActivity() const override;
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     // EventTarget interface.
-    bool dispatchEventInternal(PassRefPtrWillBeRawPtr<Event>) final;
+    DispatchEventResult dispatchEventInternal(PassRefPtrWillBeRawPtr<Event>) final;
 
 private:
     Notification(ExecutionContext*, const WebNotificationData&);
 
     void scheduleShow();
 
     // Calling show() may start asynchronous operation. If this object has
     // a V8 wrapper, hasPendingActivity() prevents the wrapper from being
     // collected while m_state is Showing, and so this instance stays alive
     // until the operation completes. Otherwise, you need to hold a ref on this
@@ skipping 24 matching lines @@
     void setState(NotificationState state) { m_state = state; }
 
     NotificationState m_state;
 
     Member<AsyncMethodRunner<Notification>> m_asyncRunner;
 };
 
 } // namespace blink
 
 #endif // Notification_h