[Extensions Bindings] Introduce a supportsLazyListeners property

extensions/renderer/resources/context_menus_handlers.js

 // Copyright 2015 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.
 
 // Implementation of custom bindings for the contextMenus API.
 // This is used to implement the contextMenus API for extensions and for the
 // <webview> tag (see chrome_web_view_experimental.js).
 
 var contextMenuNatives = requireNative('context_menus');
 var sendRequest = bindingUtil ?
     $Function.bind(bindingUtil.sendRequest, bindingUtil) :
     require('sendRequest').sendRequest;
 var hasLastError = bindingUtil ?
     $Function.bind(bindingUtil.hasLastError, bindingUtil) :
     require('lastError').hasError;
 
 var jsEvent;
-function createNewEvent(name) {
+function createNewEvent(name, isWebview) {
+  var supportsLazyListeners = !isWebview;
   if (bindingUtil) {
+    var supportsFilters = false;

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

Pull this out after line 19 and use it for eventOpts below too?

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

Wasn't like this previously because supportsFilters is false by default in JS. 
But, doesn't hurt to put it in, so done.

     // Native custom events ignore schema.
-    return bindingUtil.createCustomEvent(name, undefined, undefined);
+    return bindingUtil.createCustomEvent(name, undefined, supportsFilters,
+                                         supportsLazyListeners);
   }
   if (!jsEvent)
     jsEvent = require('event_bindings').Event;
+  var eventOpts =
+      { __proto__: null, supportsLazyListeners: supportsLazyListeners };

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

I don't remember style guide put space after {, is this clang format? Does it
work for JS?

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

I think clang-format doesn't (though JS support for that is still pretty
experimental).  But also our resources files *definitely* don't follow clang
format. :) (though they perhaps should!)  But, in either case, adding in
supportsFilters makes this moot.

   return new jsEvent(name);

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

Should we not use eventOpts here?

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

We should!  Thanks for catching this.  I've expanded the test to catch this as
well (since it would have been a bug).  (I mistakenly thought that
webview.contextMenus.onClick.addListener would have done the trick - apparently
we also need to test webview.contextMenus.create({onclick: function() {}});)

 }
 
 // Add the bindings to the contextMenus API.
 function createContextMenusHandlers(isWebview) {
   var eventName = isWebview ? 'webViewInternal.contextMenus' : 'contextMenus';
   // Some dummy value for chrome.contextMenus instances.
   // Webviews use positive integers, and 0 to denote an invalid webview ID.
   // The following constant is -1 to avoid any conflicts between webview IDs and
   // extensions.
   var INSTANCEID_NON_WEBVIEW = -1;
@@ skipping 10 matching lines @@
       }
 
       $Function.apply(handleCallback, null, arguments);
       if (extensionCallback)
         extensionCallback();
     };
   }
 
   var contextMenus = { __proto__: null };
   contextMenus.handlers = { __proto__: null };
-  contextMenus.event = createNewEvent(eventName);
+  contextMenus.event = createNewEvent(eventName, isWebview);
 
   contextMenus.getIdFromCreateProperties = function(createProperties) {
     if (typeof createProperties.id !== 'undefined')
       return createProperties.id;
     return createProperties.generatedId;
   };
 
   contextMenus.handlersForId = function(instanceId, id) {
     if (!contextMenus.handlers[instanceId]) {
       contextMenus.handlers[instanceId] = {
@@ skipping 122 matching lines @@
     sendRequest(name, $Array.from(arguments),
                 bindingUtil ? undefined : this.definition.parameters, optArgs);
   };
 
   return {
     requestHandlers: requestHandlers,
   };
 }
 
 exports.$set('create', createContextMenusHandlers);