[Extensions Bindings] Introduce a supportsLazyListeners property

extensions/renderer/resources/app_window_custom_bindings.js

Index: extensions/renderer/resources/app_window_custom_bindings.js
diff --git a/extensions/renderer/resources/app_window_custom_bindings.js b/extensions/renderer/resources/app_window_custom_bindings.js
index 2432366ca1951473cce343a6c0a8c5ce986741fd..05bee62fd59a88f14979bf10408f5f63bdc7e571 100644
--- a/extensions/renderer/resources/app_window_custom_bindings.js
+++ b/extensions/renderer/resources/app_window_custom_bindings.js
@@ -22,8 +22,11 @@ if (!apiBridge)
 var jsEvent;
 function createAnonymousEvent() {
   if (bindingUtil) {
+    var supportsFilters = false;
+    var supportsLazyListeners = false;

[lazyboy, 2017/07/14 00:04:42]

Shouldn't this be true?

[Devlin, 2017/07/14 15:37:54]

Nope - anonymous events should never support lazy listeners - it wouldn't make
sense.  They have no name, and so we'd have no way of identifying a listener (or
an event instance) for them.  In JS, this is handled here:
https://chromium.googlesource.com/chromium/src/+/52a9ace924868ad72ad5e28fc05d...

     // Native custom events ignore schema.
-    return bindingUtil.createCustomEvent(undefined, undefined, false);
+    return bindingUtil.createCustomEvent(undefined, undefined, supportsFilters,
+                                         supportsLazyListeners);
   }
   if (!jsEvent)
     jsEvent = require('event_bindings').Event;