Make V8ValueConverter.FromV8Value behave similarly to JSON.stringify

chrome/renderer/resources/extensions/context_menus_custom_bindings.js

Index: chrome/renderer/resources/extensions/context_menus_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/context_menus_custom_bindings.js b/chrome/renderer/resources/extensions/context_menus_custom_bindings.js
index 9e4016a468b138375d96b4205388cd21bd739f7d..9bc788c2c67210629b8bbc07ffe30e4e8f7b9bd3 100644
--- a/chrome/renderer/resources/extensions/context_menus_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/context_menus_custom_bindings.js
@@ -48,10 +48,14 @@ chromeHidden.registerCustomHook('contextMenus', function(bindingsAPI) {
     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]);
   });