Bindings: Require [CachedAttribute] method to be const

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

 {% from 'utilities.cpp.tmpl' import declare_enum_validation_variable, v8_value_to_local_cpp_value %}
 
 {##############################################################################}
 {% macro attribute_getter(attribute, world_suffix) %}
 static void {{attribute.name}}AttributeGetter{{world_suffix}}(
 {%- if attribute.is_data_type_property %}
 const v8::PropertyCallbackInfo<v8::Value>& info
 {%- else %}
 const v8::FunctionCallbackInfo<v8::Value>& info
 {%- endif %}) {
@@ skipping 45 matching lines @@
   {% else %}
   {{cpp_class}}* impl = {{v8_class}}::toImpl(holder);
   {% endif %}{# local_dom_window_only #}
   {% endif %}{# not attribute.is_static #}
 
   {% if attribute.cached_attribute_validation_method %}
   // [CachedAttribute]
   V8PrivateProperty::Symbol propertySymbol =
       V8PrivateProperty::GetSymbol(info.GetIsolate(),
           "{{cpp_class}}#{{attribute.name.capitalize()}}");
-  if (!impl->{{attribute.cached_attribute_validation_method}}()) {
+  if (!static_cast<const {{cpp_class}}*>(impl)->{{attribute.cached_attribute_validation_method}}()) {
     v8::Local<v8::Value> v8Value = propertySymbol.GetOrUndefined(holder);
     if (!v8Value->IsUndefined()) {
       V8SetReturnValue(info, v8Value);
       return;
     }
   }
   {% endif %}
 
   {% if attribute.is_check_security_for_receiver and not attribute.is_data_type_property %}
   // Perform a security check for the receiver object.
@@ skipping 502 matching lines @@
 static const V8DOMConfiguration::AccessorConfiguration accessorConfiguration[] = {
   {{accessor_configuration(attribute)}}
 };
 for (const auto& accessorConfig : accessorConfiguration)
   V8DOMConfiguration::InstallAccessor(isolate, world, v8::Local<v8::Object>(), prototypeObject, interfaceObject, signature, accessorConfig);
 {% endfilter %}{# runtime_enabled #}
 {% endfilter %}{# secure_context #}
 {% endfilter %}{# exposed #}
 {% endfor %}
 {% endmacro %}