IDL: Values for dictionaries should be a object, null or undefined

Source/bindings/templates/methods.cpp

 {##############################################################################}
 {% macro generate_method(method, world_suffix) %}
 {% filter conditional(method.conditional_string) %}
 static void {{method.name}}{{method.overload_index}}Method{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     {# Local variables #}
     {% if method.has_exception_state %}
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "{{method.name}}", "{{interface_name}}", info.Holder(), info.GetIsolate());
     {% endif %}
     {# Overloaded methods have length checked during overload resolution #}
@@ skipping 82 matching lines @@
 {%- endif %}{# argument.idl_type == 'EventListener' #}
 {%- else %}
 {{argument.cpp_type}} {{argument.name}}
 {%- endif %}
 {% endmacro %}
 
 
 {######################################}
 {% macro generate_argument(method, argument, world_suffix) %}
 {% if argument.is_optional and not argument.has_default and
-      argument.idl_type != 'Dictionary' and
+      not argument.is_dictionary and
       not argument.is_callback_interface %}
 {# Optional arguments without a default value generate an early call with
    fewer arguments if they are omitted.
    Optional Dictionary arguments default to empty dictionary. #}
 if (UNLIKELY(info.Length() <= {{argument.index}})) {
     {% if world_suffix %}
     {{cpp_method_call(method, argument.v8_set_return_value_for_main_world, argument.cpp_value) | indent}}
     {% else %}
     {{cpp_method_call(method, argument.v8_set_return_value, argument.cpp_value) | indent}}
     {% endif %}
@@ skipping 53 matching lines @@
 }
 {% 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_type_error(method, '"parameter %s is not of type \'%s\'."' %
                                    (argument.index + 1, argument.idl_type)) | indent(8)}}
         return;
     }
     {{argument.name}}.append(V8{{argument.idl_type}}::toImpl(v8::Handle<v8::Object>::Cast(info[i])));
 }
+{% elif argument.is_dictionary %}
+{# Dictionaries must have type Undefined, Null or Object:
+http://heycam.github.io/webidl/#es-dictionary #}
+if (!isUndefinedOrNull(info[{{argument.index}}]) && !info[{{argument.index}}]->IsObject()) {
+    {{throw_type_error(method, '"parameter %s (\'%s\') is not an object."' %
+                               (argument.index + 1, argument.name)) | indent}}
+    return;
+}
+{{argument.v8_value_to_local_cpp_value}};
 {% else %}{# argument.is_nullable #}
 {{argument.v8_value_to_local_cpp_value}};
 {% endif %}{# argument.is_nullable #}
 {# Type checking, possibly throw a TypeError, per:
    http://www.w3.org/TR/WebIDL/#es-type-mapping #}
 {% if argument.has_type_checking_unrestricted %}
 {# Non-finite floating point values (NaN, +Infinity or −Infinity), per:
    http://heycam.github.io/webidl/#es-float
    http://heycam.github.io/webidl/#es-double #}
 if (!std::isfinite({{argument.name}})) {
     {{throw_type_error(method, '"%s parameter %s is non-finite."' %
                                (argument.idl_type, argument.index + 1)) | indent}}
     return;
 }
 {% elif argument.enum_validation_expression %}
 {# Invalid enum values: http://www.w3.org/TR/WebIDL/#idl-enums #}
 String string = {{argument.name}};
 if (!({{argument.enum_validation_expression}})) {
     {{throw_type_error(method,
           '"parameter %s (\'" + string + "\') is not a valid enum value."' %
               (argument.index + 1)) | indent}}
     return;
 }
-{% elif argument.idl_type in ['Dictionary', 'Promise'] %}
-{# Dictionaries must have type Undefined, Null or Object:
-http://heycam.github.io/webidl/#es-dictionary
-We also require this for our implementation of promises, though not in spec:
+{% elif argument.idl_type == 'Promise' %}
+{# We require this for our implementation of promises, though not in spec:
 http://heycam.github.io/webidl/#es-promise #}
 if (!{{argument.name}}.isUndefinedOrNull() && !{{argument.name}}.isObject()) {
     {{throw_type_error(method, '"parameter %s (\'%s\') is not an object."' %
                                (argument.index + 1, argument.name)) | indent}}
     return;
 }
 {% endif %}
 {% endmacro %}
 
 
@@ skipping 416 matching lines @@
   if method.is_per_world_bindings else '0' %}
 {% set property_attribute =
   'static_cast<v8::PropertyAttribute>(%s)' % ' | '.join(method.property_attributes)
   if method.property_attributes else 'v8::None' %}
 {% set only_exposed_to_private_script = 'V8DOMConfiguration::OnlyExposedToPrivateScript' if method.only_exposed_to_private_script else 'V8DOMConfiguration::ExposedToAllScripts' %}
 static const V8DOMConfiguration::MethodConfiguration {{method.name}}MethodConfiguration = {
     "{{method.name}}", {{method_callback}}, {{method_callback_for_main_world}}, {{method.length}}, {{only_exposed_to_private_script}},
 };
 V8DOMConfiguration::installMethod({{method.function_template}}, {{method.signature}}, {{property_attribute}}, {{method.name}}MethodConfiguration, isolate);
 {%- endmacro %}