bindings: Throw a TypeError when a given callback function isn't callable

third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl

 {% from 'utilities.cpp.tmpl' import declare_enum_validation_variable, v8_value_to_local_cpp_value %}
 
 {##############################################################################}
 {% macro generate_method(method, world_suffix) %}
 static void {{method.name}}{{method.overload_index}}Method{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info) {
   {% filter format_remove_duplicates([
       'ExceptionState exceptionState',
       'ScriptState* scriptState = ']) %}
   {% set define_exception_state -%}
   ExceptionState exceptionState(info.GetIsolate(), ExceptionState::ExecutionContext, "{{interface_name}}", "{{method.name}}");
@@ skipping 159 matching lines @@
 }
 {% else %}{# argument.is_optional #}
 if (info.Length() <= {{argument.index}} || !{% if argument.is_nullable %}(info[{{argument.index}}]->IsFunction() || info[{{argument.index}}]->IsNull()){% else %}info[{{argument.index}}]->IsFunction(){% endif %}) {
   {{throw_argument_error(method, argument, "The callback provided as parameter %(index)d is not a function.")}}
   return;
 }
 {{argument.name}} = {% if argument.is_nullable %}info[{{argument.index}}]->IsNull() ? nullptr : {% endif %}V8{{argument.idl_type}}::create(v8::Local<v8::Function>::Cast(info[{{argument.index}}]), ScriptState::current(info.GetIsolate()));
 {% endif %}{# argument.is_optional #}
 {% endif %}{# argument.idl_type == 'EventListener' #}
 {% elif argument.is_callback_function %}
-if (!info[{{argument.index}}]->IsFunction(){% if argument.is_nullable %} && !info[{{argument.index}}]->IsNull(){% endif %}) {
+if (!info[{{argument.index}}]->IsObject() || !v8::Local<v8::Object>::Cast(info[{{argument.index}}])->IsCallable()) {
   {{throw_argument_error(method, argument, "The callback provided as parameter %(index)d is not a function.")}}
   return;
 }
 {{v8_value_to_local_cpp_value(argument)}}
 {% elif argument.is_variadic_wrapper_type %}
 for (int i = {{argument.index}}; i < info.Length(); ++i) {
   if (!V8{{argument.idl_type}}::hasInstance(info[i], info.GetIsolate())) {
     {{throw_argument_error(method, argument, "parameter %(index)d is not of type '%(type)s'.")}}
     return;
   }
@@ skipping 446 matching lines @@
                           if method.overloads else
                           method.runtime_enabled_feature_name) %}
 const V8DOMConfiguration::MethodConfiguration {{method.name}}MethodConfiguration = {{method_configuration(method)}};
 V8DOMConfiguration::installMethod(isolate, world, v8::Local<v8::Object>(), prototypeObject, interfaceObject, signature, {{method.name}}MethodConfiguration);
 {% endfilter %}{# runtime_enabled() #}
 {% endfilter %}{# exposed() #}
 {% endfilter %}{# secure_context() #}
 {% endfor %}
 {% endif %}
 {%- endmacro %}