[bindings] Implement an ExperimentEnabled IDL extended attribute.

third_party/WebKit/Source/bindings/tests/results/core/V8TestInterface.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file has been auto-generated by code_generator_v8.py. DO NOT MODIFY!
 
 #include "V8TestInterface.h"
 
 #if ENABLE(CONDITION)
 #include "bindings/core/v8/ExceptionState.h"
@@ skipping 12 matching lines @@
 #include "bindings/core/v8/V8TestInterface.h"
 #include "bindings/core/v8/V8TestInterface2.h"
 #include "bindings/core/v8/V8TestInterfaceEmpty.h"
 #include "bindings/core/v8/V8Window.h"
 #include "bindings/tests/idls/core/TestImplements2.h"
 #include "bindings/tests/idls/core/TestImplements3Implementation.h"
 #include "bindings/tests/idls/core/TestPartialInterface.h"
 #include "bindings/tests/idls/core/TestPartialInterfaceImplementation.h"
 #include "core/dom/ContextFeatures.h"
 #include "core/dom/Document.h"
+#include "core/experiments/ExperimentalFeatures.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/UseCounter.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/TraceEvent.h"
 #include "wtf/GetPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/build_config.h"
 
@@ skipping 42 matching lines @@
         const WrapperTypeInfo* wrapperTypeInfo = WrapperTypeInfo::unwrap(data);
         if (!wrapperTypeInfo)
             break;
         TestInterfaceImplementationCreateDataProperty(v8String(info.GetIsolate(), wrapperTypeInfo->interfaceName), v8Value, info);
     } while (false); // do ... while (false) just for use of break
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void testInterfaceAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueFast(info, WTF::getPtr(impl->testInterfaceAttribute()), impl);
 }
 
 static void testInterfaceAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
     UseCounter::countIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::V8TestInterface_TestInterfaceAttribute_AttributeGetter);
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::testInterfaceAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void testInterfaceAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "testInterfaceAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     TestInterfaceImplementation* cppValue = V8TestInterface::toImplWithTypeCheck(info.GetIsolate(), v8Value);
@@ skipping 22 matching lines @@
 
 static void testInterfaceConstructorAttributeAttributeSetterCallback(v8::Local<v8::Name>, v8::Local<v8::Value> v8Value, const v8::PropertyCallbackInfo<void>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::testInterfaceConstructorAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void doubleAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValue(info, impl->doubleAttribute());
 }
 
 static void doubleAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::doubleAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void doubleAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "doubleAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     double cppValue = toRestrictedDouble(info.GetIsolate(), v8Value, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setDoubleAttribute(cppValue);
 }
 
 static void doubleAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::doubleAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void floatAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValue(info, impl->floatAttribute());
 }
 
 static void floatAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::floatAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void floatAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "floatAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     float cppValue = toRestrictedFloat(info.GetIsolate(), v8Value, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setFloatAttribute(cppValue);
 }
 
 static void floatAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::floatAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void unrestrictedDoubleAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValue(info, impl->unrestrictedDoubleAttribute());
 }
 
 static void unrestrictedDoubleAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::unrestrictedDoubleAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void unrestrictedDoubleAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "unrestrictedDoubleAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     double cppValue = toDouble(info.GetIsolate(), v8Value, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setUnrestrictedDoubleAttribute(cppValue);
 }
 
 static void unrestrictedDoubleAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::unrestrictedDoubleAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void unrestrictedFloatAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValue(info, impl->unrestrictedFloatAttribute());
 }
 
 static void unrestrictedFloatAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::unrestrictedFloatAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void unrestrictedFloatAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "unrestrictedFloatAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     float cppValue = toFloat(info.GetIsolate(), v8Value, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setUnrestrictedFloatAttribute(cppValue);
 }
 
 static void unrestrictedFloatAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::unrestrictedFloatAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void testEnumAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueString(info, impl->testEnumAttribute(), info.GetIsolate());
 }
 
 static void testEnumAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::testEnumAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void testEnumAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "testEnumAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     V8StringResource<> cppValue = v8Value;
@@ skipping 15 matching lines @@
 static void testEnumAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::testEnumAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void stringOrDoubleAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     StringOrDouble result;
     impl->stringOrDoubleAttribute(result);
     v8SetReturnValue(info, result);
 }
 
 static void stringOrDoubleAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::stringOrDoubleAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void stringOrDoubleAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "stringOrDoubleAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     StringOrDouble cppValue;
     V8StringOrDouble::toImpl(info.GetIsolate(), v8Value, cppValue, UnionTypeConversionMode::NotNullable, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setStringOrDoubleAttribute(cppValue);
 }
 
 static void stringOrDoubleAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::stringOrDoubleAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void conditionalLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueInt(info, impl->conditionalLongAttribute());
 }
 
 static void conditionalLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::conditionalLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void conditionalLongAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "conditionalLongAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     int cppValue = toInt32(info.GetIsolate(), v8Value, NormalConversion, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setConditionalLongAttribute(cppValue);
 }
 
 static void conditionalLongAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::conditionalLongAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void conditionalReadOnlyLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueInt(info, impl->conditionalReadOnlyLongAttribute());
 }
 
 static void conditionalReadOnlyLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::conditionalReadOnlyLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticStringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueString(info, TestInterfaceImplementation::staticStringAttribute(), info.GetIsolate());
 }
 
 static void staticStringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::staticStringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticStringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     TestInterfaceImplementation::setStaticStringAttribute(cppValue);
 }
 
 static void staticStringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::staticStringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticReturnDOMWrapperAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValue(info, TestInterfaceImplementation::staticReturnDOMWrapperAttribute(), info.GetIsolate()->GetCurrentContext()->Global());
 }
 
 static void staticReturnDOMWrapperAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::staticReturnDOMWrapperAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticReturnDOMWrapperAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "staticReturnDOMWrapperAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* cppValue = V8TestInterface::toImplWithTypeCheck(info.GetIsolate(), v8Value);
     if (!cppValue) {
         exceptionState.throwTypeError("The provided value is not of type 'TestInterface'.");
         exceptionState.throwIfNeeded();
         return;
     }
     TestInterfaceImplementation::setStaticReturnDOMWrapperAttribute(WTF::getPtr(cppValue));
 }
 
 static void staticReturnDOMWrapperAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::staticReturnDOMWrapperAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticReadOnlyStringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueString(info, TestInterfaceImplementation::staticReadOnlyStringAttribute(), info.GetIsolate());
 }
 
 static void staticReadOnlyStringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::staticReadOnlyStringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticReadOnlyReturnDOMWrapperAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     RefPtr<TestInterfaceImplementation> cppValue(TestInterfaceImplementation::staticReadOnlyReturnDOMWrapperAttribute());
     if (cppValue && DOMDataStore::setReturnValue(info.GetReturnValue(), cppValue.get()))
         return;
     v8::Local<v8::Value> v8Value(toV8(cppValue.get(), holder, info.GetIsolate()));
     if (!v8Value.IsEmpty()) {
         V8HiddenValue::setHiddenValue(ScriptState::current(info.GetIsolate()), holder, v8AtomicString(info.GetIsolate(), "staticReadOnlyReturnDOMWrapperAttribute"), v8Value);
         v8SetReturnValue(info, v8Value);
     }
 }
 
 static void staticReadOnlyReturnDOMWrapperAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::staticReadOnlyReturnDOMWrapperAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticConditionalReadOnlyLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueInt(info, TestInterfaceImplementation::staticConditionalReadOnlyLongAttribute());
 }
 
 static void staticConditionalReadOnlyLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::staticConditionalReadOnlyLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void legacyInterfaceTypeCheckingAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueFast(info, WTF::getPtr(impl->legacyInterfaceTypeCheckingAttribute()), impl);
 }
 
 static void legacyInterfaceTypeCheckingAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::legacyInterfaceTypeCheckingAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void legacyInterfaceTypeCheckingAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     TestInterfaceEmpty* cppValue = V8TestInterfaceEmpty::toImplWithTypeCheck(info.GetIsolate(), v8Value);
     impl->setLegacyInterfaceTypeCheckingAttribute(WTF::getPtr(cppValue));
 }
 
 static void legacyInterfaceTypeCheckingAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::legacyInterfaceTypeCheckingAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void alwaysExposedAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueInt(info, impl->alwaysExposedAttribute());
 }
 
 static void alwaysExposedAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::alwaysExposedAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void alwaysExposedAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "alwaysExposedAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     int cppValue = toInt32(info.GetIsolate(), v8Value, NormalConversion, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setAlwaysExposedAttribute(cppValue);
 }
 
 static void alwaysExposedAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::alwaysExposedAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void workerExposedAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueInt(info, impl->workerExposedAttribute());
 }
 
 static void workerExposedAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::workerExposedAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void workerExposedAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "workerExposedAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     int cppValue = toInt32(info.GetIsolate(), v8Value, NormalConversion, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setWorkerExposedAttribute(cppValue);
 }
 
 static void workerExposedAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::workerExposedAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void windowExposedAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueInt(info, impl->windowExposedAttribute());
 }
 
 static void windowExposedAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::windowExposedAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void windowExposedAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "windowExposedAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     int cppValue = toInt32(info.GetIsolate(), v8Value, NormalConversion, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     impl->setWindowExposedAttribute(cppValue);
 }
 
 static void windowExposedAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::windowExposedAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void lenientThisAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     if (!V8TestInterface::hasInstance(info.Holder(), info.GetIsolate()))
         return; // Return silently because of [LenientThis].
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValue(info, impl->lenientThisAttribute().v8Value());
 }
 
 static void lenientThisAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::lenientThisAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void lenientThisAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     if (!V8TestInterface::hasInstance(info.Holder(), info.GetIsolate()))
         return; // Return silently because of [LenientThis].
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     ScriptValue cppValue = ScriptValue(ScriptState::current(info.GetIsolate()), v8Value);
     impl->setLenientThisAttribute(cppValue);
 }
 
 static void lenientThisAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::lenientThisAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsStaticReadOnlyLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueInt(info, TestInterfaceImplementation::implementsStaticReadOnlyLongAttribute());
 }
 
 static void implementsStaticReadOnlyLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsStaticReadOnlyLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsStaticStringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueString(info, TestInterfaceImplementation::implementsStaticStringAttribute(), info.GetIsolate());
 }
 
 static void implementsStaticStringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsStaticStringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsStaticStringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     TestInterfaceImplementation::setImplementsStaticStringAttribute(cppValue);
 }
 
 static void implementsStaticStringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implementsStaticStringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsReadonlyStringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueString(info, impl->implementsReadonlyStringAttribute(), info.GetIsolate());
 }
 
 static void implementsReadonlyStringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsReadonlyStringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsStringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueString(info, impl->implementsStringAttribute(), info.GetIsolate());
 }
 
 static void implementsStringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsStringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsStringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     impl->setImplementsStringAttribute(cppValue);
 }
 
 static void implementsStringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implementsStringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsNodeAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueFast(info, WTF::getPtr(impl->implementsNodeAttribute()), impl);
 }
 
 static void implementsNodeAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsNodeAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsNodeAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "implementsNodeAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     Node* cppValue = V8Node::toImplWithTypeCheck(info.GetIsolate(), v8Value);
     if (!cppValue) {
         exceptionState.throwTypeError("The provided value is not of type 'Node'.");
         exceptionState.throwIfNeeded();
         return;
     }
     impl->setImplementsNodeAttribute(WTF::getPtr(cppValue));
 }
 
 static void implementsNodeAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implementsNodeAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsEventHandlerAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     EventListener* cppValue(impl->implementsEventHandlerAttribute());
     v8SetReturnValue(info, cppValue ? v8::Local<v8::Value>(V8AbstractEventListener::cast(cppValue)->getListenerObject(impl->executionContext())) : v8::Local<v8::Value>(v8::Null(info.GetIsolate())));
 }
 
 static void implementsEventHandlerAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsEventHandlerAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsEventHandlerAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     moveEventListenerToNewWrapper(info.GetIsolate(), holder, impl->implementsEventHandlerAttribute(), v8Value, V8TestInterface::eventListenerCacheIndex);
     impl->setImplementsEventHandlerAttribute(V8EventListenerList::getEventListener(ScriptState::current(info.GetIsolate()), v8Value, true, ListenerFindOrCreate));
 }
 
 static void implementsEventHandlerAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implementsEventHandlerAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsRuntimeEnabledNodeAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueFast(info, WTF::getPtr(impl->implementsRuntimeEnabledNodeAttribute()), impl);
 }
 
 static void implementsRuntimeEnabledNodeAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsRuntimeEnabledNodeAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsRuntimeEnabledNodeAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "implementsRuntimeEnabledNodeAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     Node* cppValue = V8Node::toImplWithTypeCheck(info.GetIsolate(), v8Value);
     if (!cppValue) {
         exceptionState.throwTypeError("The provided value is not of type 'Node'.");
         exceptionState.throwIfNeeded();
         return;
     }
     impl->setImplementsRuntimeEnabledNodeAttribute(WTF::getPtr(cppValue));
 }
 
 static void implementsRuntimeEnabledNodeAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implementsRuntimeEnabledNodeAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements2StaticStringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueString(info, TestImplements2::implements2StaticStringAttribute(), info.GetIsolate());
 }
 
 static void implements2StaticStringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implements2StaticStringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements2StaticStringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     TestImplements2::setImplements2StaticStringAttribute(cppValue);
 }
 
 static void implements2StaticStringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implements2StaticStringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements2StringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueString(info, TestImplements2::implements2StringAttribute(*impl), info.GetIsolate());
 }
 
 static void implements2StringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implements2StringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements2StringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     TestImplements2::setImplements2StringAttribute(*impl, cppValue);
 }
 
 static void implements2StringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implements2StringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements3StringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueString(info, TestImplements3Implementation::implements3StringAttribute(*impl), info.GetIsolate());
 }
 
 static void implements3StringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implements3StringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements3StringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     TestImplements3Implementation::setImplements3StringAttribute(*impl, cppValue);
 }
 
 static void implements3StringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implements3StringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements3StaticStringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueString(info, TestImplements3Implementation::implements3StaticStringAttribute(), info.GetIsolate());
 }
 
 static void implements3StaticStringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implements3StaticStringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements3StaticStringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     TestImplements3Implementation::setImplements3StaticStringAttribute(cppValue);
 }
 
 static void implements3StaticStringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::implements3StaticStringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueInt(info, TestPartialInterface::partialLongAttribute(*impl));
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialLongAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "partialLongAttribute", "TestInterface", holder, info.GetIsolate());
@@ skipping 11 matching lines @@
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::partialLongAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialStaticLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueInt(info, TestPartialInterface::partialStaticLongAttribute());
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialStaticLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialStaticLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialStaticLongAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "partialStaticLongAttribute", "TestInterface", holder, info.GetIsolate());
@@ skipping 10 matching lines @@
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::partialStaticLongAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialCallWithExecutionContextLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
     v8SetReturnValueInt(info, TestPartialInterface::partialCallWithExecutionContextLongAttribute(executionContext, *impl));
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialCallWithExecutionContextLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialCallWithExecutionContextLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialCallWithExecutionContextLongAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "partialCallWithExecutionContextLongAttribute", "TestInterface", holder, info.GetIsolate());
@@ skipping 12 matching lines @@
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::partialCallWithExecutionContextLongAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialPartialEnumTypeAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueString(info, TestPartialInterface::partialPartialEnumTypeAttribute(*impl), info.GetIsolate());
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialPartialEnumTypeAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialPartialEnumTypeAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialPartialEnumTypeAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "partialPartialEnumTypeAttribute", "TestInterface", holder, info.GetIsolate());
@@ skipping 19 matching lines @@
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::partialPartialEnumTypeAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void stringAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     String result;
     if (!V8TestInterface::PrivateScript::stringAttributeAttributeGetter(toLocalFrame(toFrameIfNotDetached(info.GetIsolate()->GetCurrentContext())), impl, &result))
         return;
     v8SetReturnValueString(info, result, info.GetIsolate());
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void stringAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::stringAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void stringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return;
     V8TestInterface::PrivateScript::stringAttributeAttributeSetter(toLocalFrame(toFrameIfNotDetached(info.GetIsolate()->GetCurrentContext())), impl, cppValue);
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void stringAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::stringAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 static void partial2LongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     v8SetReturnValueInt(info, TestPartialInterfaceImplementation::partial2LongAttribute(*impl));
 }
 
 static void partial2LongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partial2LongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void partial2LongAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "partial2LongAttribute", "TestInterface", holder, info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(holder);
     int cppValue = toInt32(info.GetIsolate(), v8Value, NormalConversion, exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
     TestPartialInterfaceImplementation::setPartial2LongAttribute(*impl, cppValue);
 }
 
 static void partial2LongAttributeAttributeSetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Value> v8Value = info[0];
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMSetter");
     TestInterfaceImplementationV8Internal::partial2LongAttributeAttributeSetter(v8Value, info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void partial2StaticLongAttributeAttributeGetter(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     v8SetReturnValueInt(info, TestPartialInterfaceImplementation::partial2StaticLongAttribute());
 }
 
 static void partial2StaticLongAttributeAttributeGetterCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMGetter");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partial2StaticLongAttributeAttributeGetter(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void partial2StaticLongAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Local<v8::Object> holder = info.Holder();
     ExceptionState exceptionState(ExceptionState::SetterContext, "partial2StaticLongAttribute", "TestInterface", holder, info.GetIsolate());
     int cppValue = toInt32(info.GetIsolate(), v8Value, NormalConversion, exceptionState);
     if (exceptionState.throwIfNeeded())
@@ skipping 23 matching lines @@
             V8ThrowException::throwTypeError(info.GetIsolate(), ExceptionMessages::failedToExecute("voidMethodTestInterfaceEmptyArg", "TestInterface", "parameter 1 is not of type 'TestInterfaceEmpty'."));
             return;
         }
     }
     impl->voidMethodTestInterfaceEmptyArg(testInterfaceEmptyArg);
 }
 
 static void voidMethodTestInterfaceEmptyArgMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::voidMethodTestInterfaceEmptyArgMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void voidMethodDoubleArgFloatArgMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "voidMethodDoubleArgFloatArg", "TestInterface", info.Holder(), info.GetIsolate());
     if (UNLIKELY(info.Length() < 2)) {
         setMinimumArityTypeError(exceptionState, 2, info.Length());
         exceptionState.throwIfNeeded();
         return;
     }
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     double doubleArg;
     float floatArg;
     {
         doubleArg = toRestrictedDouble(info.GetIsolate(), info[0], exceptionState);
         if (exceptionState.throwIfNeeded())
             return;
         floatArg = toRestrictedFloat(info.GetIsolate(), info[1], exceptionState);
         if (exceptionState.throwIfNeeded())
             return;
     }
     impl->voidMethodDoubleArgFloatArg(doubleArg, floatArg);
 }
 
 static void voidMethodDoubleArgFloatArgMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::voidMethodDoubleArgFloatArgMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void voidMethodUnrestrictedDoubleArgUnrestrictedFloatArgMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "voidMethodUnrestrictedDoubleArgUnrestrictedFloatArg", "TestInterface", info.Holder(), info.GetIsolate());
     if (UNLIKELY(info.Length() < 2)) {
         setMinimumArityTypeError(exceptionState, 2, info.Length());
         exceptionState.throwIfNeeded();
         return;
     }
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     double unrestrictedDoubleArg;
     float unrestrictedFloatArg;
     {
         unrestrictedDoubleArg = toDouble(info.GetIsolate(), info[0], exceptionState);
         if (exceptionState.throwIfNeeded())
             return;
         unrestrictedFloatArg = toFloat(info.GetIsolate(), info[1], exceptionState);
         if (exceptionState.throwIfNeeded())
             return;
     }
     impl->voidMethodUnrestrictedDoubleArgUnrestrictedFloatArg(unrestrictedDoubleArg, unrestrictedFloatArg);
 }
 
 static void voidMethodUnrestrictedDoubleArgUnrestrictedFloatArgMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::voidMethodUnrestrictedDoubleArgUnrestrictedFloatArgMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void voidMethodTestEnumArgMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "voidMethodTestEnumArg", "TestInterface", info.Holder(), info.GetIsolate());
     if (UNLIKELY(info.Length() < 1)) {
         setMinimumArityTypeError(exceptionState, 1, info.Length());
         exceptionState.throwIfNeeded();
@@ skipping 15 matching lines @@
             exceptionState.throwIfNeeded();
             return;
         }
     }
     impl->voidMethodTestEnumArg(testEnumArg);
 }
 
 static void voidMethodTestEnumArgMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::voidMethodTestEnumArgMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void voidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->voidMethod();
 }
 
 static void voidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::voidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void voidMethodMethodForMainWorld(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->voidMethod();
 }
 
 static void voidMethodMethodCallbackForMainWorld(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::voidMethodMethodForMainWorld(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void alwaysExposedMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->alwaysExposedMethod();
 }
 
 static void alwaysExposedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::alwaysExposedMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void workerExposedMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->workerExposedMethod();
 }
 
 static void workerExposedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::workerExposedMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void windowExposedMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->windowExposedMethod();
 }
 
 static void windowExposedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::windowExposedMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void alwaysExposedStaticMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation::alwaysExposedStaticMethod();
 }
 
 static void alwaysExposedStaticMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::alwaysExposedStaticMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void workerExposedStaticMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation::workerExposedStaticMethod();
 }
 
 static void workerExposedStaticMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::workerExposedStaticMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void windowExposedStaticMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation::windowExposedStaticMethod();
 }
 
 static void windowExposedStaticMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::windowExposedStaticMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void staticReturnDOMWrapperMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8SetReturnValue(info, TestInterfaceImplementation::staticReturnDOMWrapperMethod(), info.GetIsolate()->GetCurrentContext()->Global());
 }
 
 static void staticReturnDOMWrapperMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::staticReturnDOMWrapperMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void methodWithExposedAndRuntimeEnabledFlagMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->methodWithExposedAndRuntimeEnabledFlag();
 }
 
 static void methodWithExposedAndRuntimeEnabledFlagMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::methodWithExposedAndRuntimeEnabledFlagMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void overloadMethodWithExposedAndRuntimeEnabledFlag1Method(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "overloadMethodWithExposedAndRuntimeEnabledFlag", "TestInterface", info.Holder(), info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     int longArg;
     {
@@ skipping 78 matching lines @@
 
 static void methodWithExposedHavingRuntimeEnabldFlagMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->methodWithExposedHavingRuntimeEnabldFlag();
 }
 
 static void methodWithExposedHavingRuntimeEnabldFlagMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::methodWithExposedHavingRuntimeEnabldFlagMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void windowAndServiceWorkerExposedMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->windowAndServiceWorkerExposedMethod();
 }
 
 static void windowAndServiceWorkerExposedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::windowAndServiceWorkerExposedMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void voidMethodPartialOverload1Method(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->voidMethodPartialOverload();
 }
 
@@ skipping 50 matching lines @@
     TestInterfaceEmpty* testInterfaceEmptyArg;
     {
         testInterfaceEmptyArg = V8TestInterfaceEmpty::toImplWithTypeCheck(info.GetIsolate(), info[0]);
     }
     impl->legacyInterfaceTypeCheckingMethod(testInterfaceEmptyArg);
 }
 
 static void legacyInterfaceTypeCheckingMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::legacyInterfaceTypeCheckingMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsVoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     impl->implementsVoidMethod();
 }
 
 static void implementsVoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsVoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsComplexMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "implementsComplexMethod", "TestInterface", info.Holder(), info.GetIsolate());
     if (UNLIKELY(info.Length() < 2)) {
         setMinimumArityTypeError(exceptionState, 2, info.Length());
         exceptionState.throwIfNeeded();
@@ skipping 18 matching lines @@
     if (exceptionState.hadException()) {
         exceptionState.throwIfNeeded();
         return;
     }
     v8SetReturnValue(info, result.release());
 }
 
 static void implementsComplexMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsComplexMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsCustomVoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     V8TestInterface::implementsCustomVoidMethodMethodCustom(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implementsStaticVoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation::implementsStaticVoidMethod();
 }
 
 static void implementsStaticVoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implementsStaticVoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements2VoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     TestImplements2::implements2VoidMethod(*impl);
 }
 
 static void implements2VoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implements2VoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements3VoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     TestImplements3Implementation::implements3VoidMethod(*impl);
 }
 
 static void implements3VoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implements3VoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void implements3StaticVoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestImplements3Implementation::implements3StaticVoidMethod();
 }
 
 static void implements3StaticVoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::implements3StaticVoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialVoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     TestPartialInterface::partialVoidMethod(*impl);
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialVoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialVoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialStaticVoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestPartialInterface::partialStaticVoidMethod();
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialStaticVoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialStaticVoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialVoidMethodLongArgMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "partialVoidMethodLongArg", "TestInterface", info.Holder(), info.GetIsolate());
     if (UNLIKELY(info.Length() < 1)) {
         setMinimumArityTypeError(exceptionState, 1, info.Length());
         exceptionState.throwIfNeeded();
         return;
     }
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     int longArg;
     {
         longArg = toInt32(info.GetIsolate(), info[0], NormalConversion, exceptionState);
         if (exceptionState.throwIfNeeded())
             return;
     }
     TestPartialInterface::partialVoidMethodLongArg(*impl, longArg);
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialVoidMethodLongArgMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialVoidMethodLongArgMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialCallWithExecutionContextRaisesExceptionVoidMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "partialCallWithExecutionContextRaisesExceptionVoidMethod", "TestInterface", info.Holder(), info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
     TestPartialInterface::partialCallWithExecutionContextRaisesExceptionVoidMethod(executionContext, *impl, exceptionState);
     if (exceptionState.hadException()) {
         exceptionState.throwIfNeeded();
         return;
     }
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialCallWithExecutionContextRaisesExceptionVoidMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialCallWithExecutionContextRaisesExceptionVoidMethodMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialVoidMethodPartialCallbackTypeArgMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     if (UNLIKELY(info.Length() < 1)) {
         V8ThrowException::throwException(createMinimumArityTypeErrorForMethod(info.GetIsolate(), "partialVoidMethodPartialCallbackTypeArg", "TestInterface", 1, info.Length()), info.GetIsolate());
         return;
     }
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     ScriptValue partialCallbackTypeArg;
     {
         if (!info[0]->IsFunction()) {
             V8ThrowException::throwTypeError(info.GetIsolate(), ExceptionMessages::failedToExecute("partialVoidMethodPartialCallbackTypeArg", "TestInterface", "The callback provided as parameter 1 is not a function."));
             return;
         }
         partialCallbackTypeArg = ScriptValue(ScriptState::current(info.GetIsolate()), info[0]);
     }
     TestPartialInterface::partialVoidMethodPartialCallbackTypeArg(*impl, partialCallbackTypeArg);
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void partialVoidMethodPartialCallbackTypeArgMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::partialVoidMethodPartialCallbackTypeArgMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void shortMethodWithShortArgumentImplementedInPrivateScriptMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "shortMethodWithShortArgumentImplementedInPrivateScript", "TestInterface", info.Holder(), info.GetIsolate());
     if (UNLIKELY(info.Length() < 1)) {
@@ skipping 12 matching lines @@
     if (!V8TestInterface::PrivateScript::shortMethodWithShortArgumentImplementedInPrivateScriptMethod(toLocalFrame(toFrameIfNotDetached(info.GetIsolate()->GetCurrentContext())), impl, value, &result))
         return;
     v8SetReturnValueInt(info, result);
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 #if ENABLE(PARTIAL_CONDITION)
 static void shortMethodWithShortArgumentImplementedInPrivateScriptMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::shortMethodWithShortArgumentImplementedInPrivateScriptMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 #endif // ENABLE(PARTIAL_CONDITION)
 
 static void partial2VoidMethod1Method(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     TestPartialInterfaceImplementation::partial2VoidMethod(*impl);
 }
@@ skipping 168 matching lines @@
     if (exceptionState.hadException()) {
         exceptionState.throwIfNeeded();
         return;
     }
     v8SetReturnValue(info, result.v8Value());
 }
 
 static void toJSONMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::toJSONMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void toStringMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     v8SetReturnValueString(info, impl->toString(), info.GetIsolate());
 }
 
 static void toStringMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::toStringMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void iteratorMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "iterator", "TestInterface", info.Holder(), info.GetIsolate());
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     ScriptState* scriptState = ScriptState::current(info.GetIsolate());
     RawPtr<Iterator> result = impl->iterator(scriptState, exceptionState);
     if (exceptionState.hadException()) {
         exceptionState.throwIfNeeded();
         return;
     }
     v8SetReturnValue(info, result.release());
 }
 
 static void iteratorMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
+    ExecutionContext* executionContext = currentExecutionContext(info.GetIsolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
     TestInterfaceImplementationV8Internal::iteratorMethod(info);
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 static void indexedPropertyGetter(uint32_t index, const v8::PropertyCallbackInfo<v8::Value>& info)
 {
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     String result = impl->anonymousIndexedGetter(index);
     if (result.isNull())
         return;
@@ skipping 222 matching lines @@
     {"partial2StaticVoidMethod", TestInterfaceImplementationV8Internal::partial2StaticVoidMethodMethodCallback, 0, 0, v8::None, V8DOMConfiguration::ExposedToAllScripts, V8DOMConfiguration::OnInterface},
     {"toJSON", TestInterfaceImplementationV8Internal::toJSONMethodCallback, 0, 0, static_cast<v8::PropertyAttribute>(v8::DontEnum), V8DOMConfiguration::ExposedToAllScripts, V8DOMConfiguration::OnPrototype},
     {"toString", TestInterfaceImplementationV8Internal::toStringMethodCallback, 0, 0, static_cast<v8::PropertyAttribute>(v8::DontEnum), V8DOMConfiguration::ExposedToAllScripts, V8DOMConfiguration::OnPrototype},
 };
 
 void V8TestInterface::installV8TestInterfaceTemplate(v8::Local<v8::FunctionTemplate> functionTemplate, v8::Isolate* isolate)
 {
     functionTemplate->ReadOnlyPrototype();
 
     v8::Local<v8::Signature> defaultSignature;
-    if (!RuntimeEnabledFeatures::featureNameEnabled())
-        defaultSignature = V8DOMConfiguration::installDOMClassTemplate(isolate, functionTemplate, "TestInterface", V8TestInterfaceEmpty::domTemplate(isolate), V8TestInterface::internalFieldCount, 0, 0, 0, 0, 0, 0);
-    else
-        defaultSignature = V8DOMConfiguration::installDOMClassTemplate(isolate, functionTemplate, "TestInterface", V8TestInterfaceEmpty::domTemplate(isolate), V8TestInterface::internalFieldCount,
-            V8TestInterfaceAttributes, WTF_ARRAY_LENGTH(V8TestInterfaceAttributes),
-            V8TestInterfaceAccessors, WTF_ARRAY_LENGTH(V8TestInterfaceAccessors),
-            V8TestInterfaceMethods, WTF_ARRAY_LENGTH(V8TestInterfaceMethods));
+    defaultSignature = V8DOMConfiguration::installDOMClassTemplate(isolate, functionTemplate, "TestInterface", V8TestInterfaceEmpty::domTemplate(isolate), V8TestInterface::internalFieldCount,
+        V8TestInterfaceAttributes, WTF_ARRAY_LENGTH(V8TestInterfaceAttributes),
+        V8TestInterfaceAccessors, WTF_ARRAY_LENGTH(V8TestInterfaceAccessors),
+        V8TestInterfaceMethods, WTF_ARRAY_LENGTH(V8TestInterfaceMethods));
     v8::Local<v8::ObjectTemplate> instanceTemplate = functionTemplate->InstanceTemplate();
     ALLOW_UNUSED_LOCAL(instanceTemplate);
     v8::Local<v8::ObjectTemplate> prototypeTemplate = functionTemplate->PrototypeTemplate();
     ALLOW_UNUSED_LOCAL(prototypeTemplate);
     ExecutionContext* context = currentExecutionContext(isolate);
     ALLOW_UNUSED_LOCAL(context);
     if (RuntimeEnabledFeatures::featureNameEnabled()) {
         const V8DOMConfiguration::AccessorConfiguration accessorconditionalReadOnlyLongAttributeConfiguration = \
         {"conditionalReadOnlyLongAttribute", TestInterfaceImplementationV8Internal::conditionalReadOnlyLongAttributeAttributeGetterCallback, 0, 0, 0, 0, v8::DEFAULT, static_cast<v8::PropertyAttribute>(v8::None), V8DOMConfiguration::ExposedToAllScripts, V8DOMConfiguration::OnPrototype, V8DOMConfiguration::CheckHolder};
         V8DOMConfiguration::installAccessor(isolate, instanceTemplate, prototypeTemplate, functionTemplate, defaultSignature, accessorconditionalReadOnlyLongAttributeConfiguration);
@@ skipping 238 matching lines @@
         return false;
     ScriptState* scriptStateInUserScript = ScriptState::forMainWorld(frame);
     if (!scriptState->contextIsValid())
         return false;
 
     ScriptState::Scope scope(scriptState);
     v8::Local<v8::Value> holder = toV8(holderImpl, scriptState->context()->Global(), scriptState->isolate());
     if (holder.IsEmpty())
         return false;
 
+    ExecutionContext* executionContext = currentExecutionContext(scriptState->isolate());
+    String errorMessage;
+    if (!ExperimentalFeatures::featureNameEnabled(executionContext, errorMessage)) {
+         v8SetReturnValue(info, v8::Undefined(info.GetIsolate()));
+         toDocument(executionContext)->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, errorMessage));
+         return;
+    }
+
     ExceptionState exceptionState(ExceptionState::GetterContext, "stringAttribute", "TestInterfaceImplementation", scriptState->context()->Global(), scriptState->isolate());
     v8::Local<v8::Value> v8Value = PrivateScriptRunner::runDOMAttributeGetter(scriptState, scriptStateInUserScript, "TestInterfaceImplementation", "stringAttribute", holder);
     if (v8Value.IsEmpty())
         return false;
     V8StringResource<> cppValue = v8Value;
     if (!cppValue.prepare())
         return false;
     RELEASE_ASSERT(!exceptionState.hadException());
     *result = cppValue;
     return true;
@@ skipping 55 matching lines @@
     TestInterfaceImplementationV8Internal::partial2VoidMethodMethodForPartialInterface = method;
 }
 
 void V8TestInterface::registerPartial2StaticVoidMethodMethodForPartialInterface(void (*method)(const v8::FunctionCallbackInfo<v8::Value>&))
 {
     TestInterfaceImplementationV8Internal::partial2StaticVoidMethodMethodForPartialInterface = method;
 }
 
 } // namespace blink
 #endif // ENABLE(CONDITION)