Registers a new user script message handler in script world with name @world_name.
See webkit_user_content_manager_register_script_message_handler() for full description.
Registering a script message handler will fail if the requested
name has been already registered before.
Registers a new user script message handler in script world with name @world_name. See webkit_user_content_manager_register_script_message_handler() for full description.
Registering a script message handler will fail if the requested name has been already registered before.