binding: Returns a reject promise when |this| is not of the type.

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}}");
   {%- endset %}
 
   {% set function_call = func_call_with_prep_of_args(method, world_suffix) %}
 
-  {% if 'exceptionState' in function_call %}
+  {% if 'exceptionState' in function_call or
+        (method.returns_promise and not method.is_static) %}
   {{define_exception_state}}
   {% if method.returns_promise %}
   ExceptionToRejectPromiseScope rejectPromiseScope(info, exceptionState);
   {% endif %}
   {% endif %}
 
   {% if not method.is_static %}
+  {% if method.returns_promise %}
+  // V8DOMConfiguration::DoNotCheckHolder
+  // Make sure that info.Holder() really points to an instance of the type.
+  if (!{{v8_class}}::hasInstance(info.Holder(), info.GetIsolate())) {
+    {{throw_type_error(method, '"Illegal invocation"')}}
+    return;
+  }
+  {% endif %}
   {{cpp_class}}* impl = {{v8_class}}::toImpl(info.Holder());
   {% endif %}
 
   {# Security checks #}
   {% if method.is_check_security_for_receiver %}
   {{define_exception_state}}
   {% if interface_name == 'EventTarget' %}
   // Performance hack for EventTarget.  Checking whether it's a Window or not
   // prior to the call to BindingSecurity::shouldAllowAccessTo increases 30%
   // of speed performance on Android Nexus 7 as of Dec 2015.  ALWAYS_INLINE
@@ skipping 593 matching lines @@
 {% from 'utilities.cpp.tmpl' import property_location %}
 {% set method_callback =
        '%sV8Internal::%sMethodCallback' % (cpp_class_or_partial, method.name) %}
 {% set method_callback_for_main_world =
        '%sV8Internal::%sMethodCallbackForMainWorld' % (cpp_class_or_partial, method.name)
        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' %}
-{"{{method.name}}", {{method_callback}}, {{method_callback_for_main_world}}, {{method.length}}, {{property_attribute}}, {{only_exposed_to_private_script}}, {{property_location(method)}}}
+{% set holder_check = 'V8DOMConfiguration::DoNotCheckHolder'
+       if method.returns_promise else 'V8DOMConfiguration::CheckHolder' %}
+{"{{method.name}}", {{method_callback}}, {{method_callback_for_main_world}}, {{method.length}}, {{property_attribute}}, {{only_exposed_to_private_script}}, {{property_location(method)}}, {{holder_check}}}
 {%- endmacro %}
 
 
 {######################################}
 {% macro install_custom_signature(method, instance_template, prototype_template, interface_template, signature) %}
 const V8DOMConfiguration::MethodConfiguration {{method.name}}MethodConfiguration = {{method_configuration(method)}};
 V8DOMConfiguration::installMethod(isolate, world, {{instance_template}}, {{prototype_template}}, {{interface_template}}, {{signature}}, {{method.name}}MethodConfiguration);
 {%- endmacro %}
 
 
@@ skipping 15 matching lines @@
                           if method.overloads else
                           method.runtime_enabled_function) %}
 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 %}