bindings: Supports per-member [Exposed] for attributes on prototype.

Source/bindings/templates/interface.cpp

 {% extends 'interface_base.cpp' %}
 
 
 {##############################################################################}
 {% block indexed_property_getter %}
 {% if indexed_property_getter and not indexed_property_getter.is_custom %}
 {% set getter = indexed_property_getter %}
 static void indexedPropertyGetter(uint32_t index, const v8::PropertyCallbackInfo<v8::Value>& info)
 {
     {{cpp_class}}* impl = {{v8_class}}::toImpl(info.Holder());
@@ skipping 779 matching lines @@
 {
     return hasInstance(value, isolate) ? toImpl(v8::Local<v8::Object>::Cast(value)) : 0;
 }
 
 {% endblock %}
 
 
 {##############################################################################}
 {% block install_conditional_attributes %}
 {% from 'attributes.cpp' import attribute_configuration with context %}
-{% if has_conditional_attributes %}
+{% if has_conditional_attributes_on_instance %}
 void {{v8_class}}::installConditionallyEnabledProperties(v8::Local<v8::Object> instanceObject, v8::Isolate* isolate)
 {
-    v8::Local<v8::Object> prototypeObject = v8::Local<v8::Object>::Cast(instanceObject->GetPrototype());
-    ExecutionContext* context = toExecutionContext(prototypeObject->CreationContext());
-
-    {% for attribute in attributes if attribute.exposed_test %}
-    {% filter exposed(attribute.exposed_test) %}
-#error No one is actually using per-member [Exposed] extended attribute.  Not supported.  Contact to blink-reviews-bindings@ if you need.
-// TODO(yukishiino): Implement the feature again if there is a client.
-    {% endfilter %}
-    {% endfor %}
-    {% for method in methods if method.exposed_test %}
-    {% filter exposed(method.exposed_test) %}
-#error No one is actually using per-member [Exposed] extended attribute.  Not supported.  Contact to blink-reviews-bindings@ if you need.
-// TODO(yukishiino): Implement the feature again if there is a client.
-    {% endfilter %}
-    {% endfor %}
+#error TODO(yukishiino): Rename this function to prepareInstanceObject (c.f. preparePrototypeObject) and implement this function if necessary.  http://crbug.com/503508
 }
 
 {% endif %}
 {% endblock %}
 
 
 {##############################################################################}
 {% block prepare_prototype_object %}
 {% from 'methods.cpp' import install_conditionally_enabled_methods with context %}
-{% if unscopeables or conditionally_enabled_methods %}
-void {{v8_class}}::preparePrototypeObject(v8::Isolate* isolate, v8::Local<v8::Object> prototypeObject)
+{% if unscopeables or has_conditional_attributes_on_prototype or conditionally_enabled_methods %}
+void {{v8_class}}::preparePrototypeObject(v8::Isolate* isolate, v8::Local<v8::Object> prototypeObject, v8::Local<v8::FunctionTemplate> interfaceTemplate)
 {
 {% if unscopeables %}
     {{install_unscopeables() | indent}}
 {% endif %}
+{% if has_conditional_attributes_on_prototype %}
+    {{install_conditionally_enabled_attributes_on_prototype() | indent}}
+{% endif %}
 {% if conditionally_enabled_methods %}
     {{install_conditionally_enabled_methods() | indent}}
 {% endif %}
 }
 
 {% endif %}
 {% endblock %}
 
 
 {##############################################################################}
 {% macro install_unscopeables() %}
 v8::Local<v8::Context> v8Context(prototypeObject->CreationContext());
 v8::Local<v8::Name> unscopablesSymbol(v8::Symbol::GetUnscopables(isolate));
 v8::Local<v8::Object> unscopeables;
 if (v8CallBoolean(prototypeObject->HasOwnProperty(v8Context, unscopablesSymbol)))
     unscopeables = prototypeObject->Get(v8Context, unscopablesSymbol).ToLocalChecked().As<v8::Object>();
 else
     unscopeables = v8::Object::New(isolate);
 {% for name, runtime_enabled_function in unscopeables %}
 {% filter runtime_enabled(runtime_enabled_function) %}
 unscopeables->CreateDataProperty(v8Context, v8AtomicString(isolate, "{{name}}"), v8::True(isolate)).FromJust();
 {% endfilter %}
 {% endfor %}
 prototypeObject->CreateDataProperty(v8Context, unscopablesSymbol, unscopeables).FromJust();
 {% endmacro %}
 
 
 {##############################################################################}
+{% macro install_conditionally_enabled_attributes_on_prototype() %}
+{% from 'attributes.cpp' import attribute_configuration with context %}
+ExecutionContext* context = toExecutionContext(prototypeObject->CreationContext());
+v8::Local<v8::Signature> signature = v8::Signature::New(isolate, interfaceTemplate);
+{% for attribute in attributes if attribute.exposed_test and attribute.on_prototype %}
+{% filter exposed(attribute.exposed_test) %}
+static const V8DOMConfiguration::AccessorConfiguration accessorConfiguration = {{attribute_configuration(attribute)}};
+V8DOMConfiguration::installAccessor(isolate, v8::Local<v8::Object>(), prototypeObject, v8::Local<v8::Function>(), signature, accessorConfiguration);
+{% endfilter %}
+{% endfor %}
+{% endmacro %}
+
+
+{##############################################################################}
 {% block to_active_dom_object %}
 {% if is_active_dom_object %}
 ActiveDOMObject* {{v8_class}}::toActiveDOMObject(v8::Local<v8::Object> wrapper)
 {
     return toImpl(wrapper);
 }
 
 {% endif %}
 {% endblock %}
 
@@ skipping 69 matching lines @@
 }
 
 {% for method in methods if method.overloads and method.overloads.has_partial_overloads %}
 void {{v8_class}}::register{{method.name | blink_capitalize}}MethodForPartialInterface(void (*method)(const v8::FunctionCallbackInfo<v8::Value>&))
 {
     {{cpp_class}}V8Internal::{{method.name}}MethodForPartialInterface = method;
 }
 {% endfor %}
 {% endif %}
 {% endblock %}