[Extenisons Bindings] Support `unmanaged` property for events

extensions/renderer/api_event_handler.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef EXTENSIONS_RENDERER_API_EVENT_HANDLER_H_
 #define EXTENSIONS_RENDERER_API_EVENT_HANDLER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 24 matching lines @@
       base::Callback<void(const std::string& event_name,
                           binding::EventListenersChanged,
                           const base::DictionaryValue* filter,
                           bool was_manual,
                           v8::Local<v8::Context>)>;
 
   APIEventHandler(const binding::RunJSFunction& call_js,
                   const EventListenersChangedMethod& listeners_changed);
   ~APIEventHandler();
 
-  // Returns a new v8::Object for an event with the given |event_name|.
+  // Returns a new v8::Object for an event with the given |event_name|. If
+  // |notify_on_change| is true, notifies whenever listeners state is changed.
   v8::Local<v8::Object> CreateEventInstance(const std::string& event_name,
                                             bool supports_filters,
                                             int max_listeners,
+                                            bool notify_on_change,
                                             v8::Local<v8::Context> context);
 
   // Creates a new event without any name. This is used by custom bindings when
   // the entirety of the logic for the event is contained in the renderer. These
   // events do not notify of new/removed listeners or allow for dispatching
   // through FireEventInContext().
   v8::Local<v8::Object> CreateAnonymousEventInstance(
       v8::Local<v8::Context> context);
 
   // Invalidates the given |event|.
@@ skipping 34 matching lines @@
 
   // The associated EventFilter; shared across all contexts and events.
   EventFilter event_filter_;
 
   DISALLOW_COPY_AND_ASSIGN(APIEventHandler);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_API_EVENT_HANDLER_H_