[Extensions Bindings] Request JS execution from messaging bindings

extensions/renderer/resources/event.js

Index: extensions/renderer/resources/event.js
diff --git a/extensions/renderer/resources/event.js b/extensions/renderer/resources/event.js
index bc885025814b31e8eb8e2e1b7f387de3b183593c..2cbf48b9ef98cb3918edbc89d03bd2e0ce90b75e 100644
--- a/extensions/renderer/resources/event.js
+++ b/extensions/renderer/resources/event.js
@@ -54,12 +54,27 @@
 
   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;