[Extensions Bindings] Request JS execution from messaging bindings

extensions/renderer/resources/event.js

 // Copyright 2014 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.
 
 // TODO(robwu): Fix indentation.
 
   var exceptionHandler = require('uncaught_exception_handler');
   var eventNatives = requireNative('event_natives');
   var logging = requireNative('logging');
   var schemaRegistry = requireNative('schema_registry');
@@ skipping 36 matching lines @@
   // An attachment strategy for events that aren't attached to the browser.
   // This applies to events with the "unmanaged" option and events without
   // names.
   function NullAttachmentStrategy(event) {
     this.event_ = event;
   }
   $Object.setPrototypeOf(NullAttachmentStrategy.prototype, null);
 
   NullAttachmentStrategy.prototype.onAddedListener =
       function(listener) {
+    // For named events, we still inform the messaging bindings when a listener
+    // is registered to allow for native checking if a listener is registered.
+    if (this.event_.eventName &&
+        this.event_.listeners.length == 0) {
+      eventNatives.AttachUnmanagedEvent(this.event_.eventName);
+    }
   };
+
   NullAttachmentStrategy.prototype.onRemovedListener =
       function(listener) {
+    if (this.event_.eventName &&
+        this.event_.listeners.length == 0) {
+      this.detach(true);
+    }
   };
+
   NullAttachmentStrategy.prototype.detach = function(manual) {
+    if (this.event_.eventName)
+      eventNatives.DetachUnmanagedEvent(this.event_.eventName);
   };
+
   NullAttachmentStrategy.prototype.getListenersByIDs = function(ids) {
     // |ids| is for filtered events only.
     return this.event_.listeners;
   };
 
   // Handles adding/removing/dispatching listeners for unfiltered events.
   function UnfilteredAttachmentStrategy(event) {
     this.event_ = event;
   }
   $Object.setPrototypeOf(UnfilteredAttachmentStrategy.prototype, null);
@@ skipping 433 matching lines @@
       'getRules',
     ],
   });
 
   // NOTE: Event is (lazily) exposed as chrome.Event from dispatcher.cc.
   exports.$set('Event', Event);
 
   exports.$set('dispatchEvent', dispatchEvent);
   exports.$set('parseEventOptions', parseEventOptions);
   exports.$set('registerArgumentMassager', registerArgumentMassager);