Make V8ValueConverter.FromV8Value behave similarly to JSON.stringify

chrome/renderer/resources/extensions/context_menus_custom_bindings.js

 // Copyright (c) 2012 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.
 
 // Custom bindings for the contextMenus API.
 
 var contextMenus = requireNative('context_menus');
 var GetNextContextMenuId = contextMenus.GetNextContextMenuId;
 var sendRequest = require('sendRequest').sendRequest;
 
@@ skipping 30 matching lines @@
       if (onclick) {
         onclick.apply(null, arguments);
       }
     });
   };
 
   apiFunctions.setHandleRequest('create', function() {
     var args = arguments;
     var id = GetNextContextMenuId();
     args[0].generatedId = id;
-    sendRequest(this.name,
-                args,
-                this.definition.parameters,
-                {customCallback: this.customCallback});
+    var optArgs = {
+      customCallback: this.customCallback,
+      // Functions aren't usually serializable, but the browser needs to know
+      // if there's an onclick handler, so convert it to an object.
+      // TODO(kalman): write this custom binding in such a way that we don't.
+      allowFunctionsInObjects: true
+    };
+    sendRequest(this.name, args, this.definition.parameters, optArgs);
     return chromeHidden.contextMenus.getIdFromCreateProperties(args[0]);
   });
 
   apiFunctions.setCustomCallback('create', function(name, request, response) {
     if (chrome.runtime.lastError) {
       return;
     }
 
     var id = chromeHidden.contextMenus.getIdFromCreateProperties(
         request.args[0]);
@@ skipping 26 matching lines @@
 
   apiFunctions.setCustomCallback('removeAll',
                                  function(name, request, response) {
     if (chrome.runtime.lastError) {
       return;
     }
     chromeHidden.contextMenus.generatedIdHandlers = {};
     chromeHidden.contextMenus.stringIdHandlers = {};
   });
 });